T1132 — Data Encoding

# T1132 - Data Encoding

## SOC Recommendation
Investigate Data Encoding activity in the context of Command and Control: confirm scope, affected host/identity, and whether it matches expected administrative behaviour before deciding this is benign.

## D3FEND Mappings
| D3FEND Technique | Relationship | Practical SOC Action |
|---|---|---|
| User Geolocation Logon Pattern Analysis | Detect | Monitor for User Geolocation Logon Pattern Analysis indicators relevant to this technique. |
| Network Traffic Filtering | Isolate | Apply Network Traffic Filtering to contain the blast radius once this technique is observed. |

## Investigation Steps
1. Review Defender for Endpoint / Defender XDR alerts and timeline for the affected host or identity.
2. Check Sentinel analytics rules and incidents correlated with this technique.
3. Review Entra ID sign-in and audit logs if the technique involves an identity or cloud resource.

## Evidence to Collect
- Host or resource affected
- Account or identity involved
- Timestamp of the activity
- Related process, file, or network artifact
- Any preceding or follow-on alerts

## Response Actions
| Action | Risk | Automation Safe | Approval Required |
|---|---|---|---|
| Contain the affected host or account | Medium | No | Yes |
| Collect and preserve evidence | Low | Yes | No |

## KQL
```kql
let threatCategory="Powershell";
let knownUserAgentsIndicators = materialize(externaldata(UserAgent:string, Category:string)
    [ @"https://raw.githubusercontent.com/Azure/Azure-Sentinel/master/Sample%20Data/Feeds/UnusualUserAgents.csv"]
        with(format="csv", ignoreFirstRecord=True));
let knownUserAgents=toscalar(knownUserAgentsIndicators | where Category==threatCategory | where isnotempty(UserAgent) | summarize make_list(UserAgent));
let customUserAgents=toscalar(_GetWatchlist("UnusualUserAgents") | where SearchKey==threatCategory | extend UserAgent=column_ifexists("UserAgent","") | where isnotempty(UserAgent) | summarize make_list(UserAgent));
let fullUAList = array_concat(knownUserAgents,customUserAgents);
_Im_WebSession(httpuseragent_has_any=fullUAList)
| project SrcIpAddr, Url, TimeGenerated, HttpUserAgent, SrcUsername
| extend AccountName = tostring(split(SrcUsername, "@")[0]), AccountUPNSuffix = tostring(split(SrcUsername, "@")[1])
```
```kql
Cisco_Umbrella
| where EventType == "proxylogs"
| where HttpUserAgentOriginal contains "WindowsPowerShell"
| extend Message = "Windows PowerShell User Agent"
| project TimeGenerated, Message, SrcIpAddr, DstIpAddr, UrlOriginal, HttpUserAgentOriginal
```
```kql
let threshold = 15;
let NoteableEvents = SymantecEndpointProtection
| where LogType == "Agent Traffic Logs"
| where Action =~ "Blocked"
| summarize TotalBlockedEvents = count() by UserName
| where TotalBlockedEvents > threshold;
SymantecEndpointProtection
| where LogType =~ "Agent Traffic Logs"
| where Action =~ "Blocked"
| join kind=inner (NoteableEvents) on UserName
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), Total = count() by UserName, RuleName, ServerName, LocalHostIpAddr, LocalPortNumber, TrafficDirection, RemoteHostIpAddr, RemotePortNumber, ApplicationName
```

## Escalation Criteria
- Data Encoding activity observed on a privileged account or critical system.
- Activity follows or precedes other suspicious behaviour in the same investigation.
- Automated triage cannot confidently rule out malicious intent.

## False Positive Considerations
- Legitimate administrative or maintenance activity matching this pattern.
- Approved security testing or red team exercise.
- Known benign software producing similar telemetry.

Generated by SOC Response Atlas by Basyrix.

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• /api/techniques/T1132.json
• /api/recommendations/T1132.json
• /api/d3fend/T1132.json
• /api/mappings/T1132.json
• /api/confluence/T1132.md

Example curl:

curl https://atlas.basyrix.com/api/recommendations/T1132.json

Response:

{
  "technique_id": "T1132",
  "name": "Data Encoding",
  "priority": "medium",
  "status": "draft",
  "version": "0.1.0",
  "last_reviewed": "2026-07-23",
  "generated_by": "SOC Response Atlas by Basyrix",
  "tactics": [
    "Command and Control"
  ],
  "platforms": [
    "ESXi",
    "Linux",
    "macOS",
    "Windows"
  ],
  "summary": "Adversaries may encode data to make the content of command and control traffic more difficult to detect. Command and control (C2) information can be encoded using a standard data encoding system. Use of data encoding may adhere to existing protocol specifications and includes use of ASCII, Unicode, Base64, MIME, or other binary-to-text and character encoding systems. Some data encoding systems may also result in data compression, such as gzip.",
  "soc_recommendation": "Investigate Data Encoding activity in the context of Command and Control: confirm scope, affected host/identity, and whether it matches expected administrative behaviour before deciding this is benign.",
  "d3fend_mappings": [
    {
      "id": "D3-UGLPA",
      "name": "User Geolocation Logon Pattern Analysis",
      "relationship": "detect",
      "practical_action": "Monitor for User Geolocation Logon Pattern Analysis indicators relevant to this technique.",
      "tooling": [
        "Defender for Endpoint"
      ]
    },
    {
      "id": "D3-NTF",
      "name": "Network Traffic Filtering",
      "relationship": "isolate",
      "practical_action": "Apply Network Traffic Filtering to contain the blast radius once this technique is observed.",
      "tooling": [
        "Sentinel",
        "Defender for Endpoint"
      ]
    }
  ],
  "investigation_steps": {
    "microsoft": [
      "Review Defender for Endpoint / Defender XDR alerts and timeline for the affected host or identity.",
      "Check Sentinel analytics rules and incidents correlated with this technique.",
      "Review Entra ID sign-in and audit logs if the technique involves an identity or cloud resource."
    ],
    "generic": [
      "Confirm whether the observed data encoding activity matches expected administrative or application behaviour.",
      "Identify the host, account, or resource where the activity occurred and its business criticality.",
      "Check for related alerts before and after this activity to reconstruct the broader intrusion timeline.",
      "Real detection reference: \"A host is potentially running PowerShell to send HTTP(S) requests (ASIM Web Session schema)\" -- This rule identifies a web request with a user agent header known to belong PowerShell. <br>You can add custom Powershell indicating User-Agent headers using a watchlist, for more information refer to the [UnusualUserAgents Watchlist](https://aka.ms/ASimUnusualUserAgentsWatchlist).<br><br> This analytic rule uses [ASIM](https://aka.ms/AboutASIM) and supports any built-in or custom source that supports the ASIM WebSession schema (ASIM WebSession Schema)'"
    ]
  },
  "evidence_to_collect": [
    "Host or resource affected",
    "Account or identity involved",
    "Timestamp of the activity",
    "Related process, file, or network artifact",
    "Any preceding or follow-on alerts"
  ],
  "response_actions": [
    {
      "name": "Contain the affected host or account",
      "category": "Containment",
      "risk": "Medium",
      "automation_safe": false,
      "approval_required": true,
      "tool": "Defender for Endpoint / Entra ID",
      "notes": "Requires approval -- confirm malicious intent before isolating a host or disabling an account."
    },
    {
      "name": "Collect and preserve evidence",
      "category": "Investigation",
      "risk": "Low",
      "automation_safe": true,
      "approval_required": false,
      "tool": "Defender for Endpoint",
      "notes": "Safe -- read-only evidence collection."
    }
  ],
  "queries": {
    "kql": [
      {
        "name": "42436753-9944-4d70-801c-daaa4d19ddd2 — A host is potentially running PowerShell to send HTTP(S) requests (ASIM Web Session schema)",
        "description": "This rule identifies a web request with a user agent header known to belong PowerShell. <br>You can add custom Powershell indicating User-Agent headers using a watchlist, for more information refer to the [UnusualUserAgents Watchlist](https://aka.ms/ASimUnusualUserAgentsWatchlist).<br><br> This analytic rule uses [ASIM](https://aka.ms/AboutASIM) and supports any built-in or custom source that supports the ASIM WebSession schema (ASIM WebSession Schema)' (Source: Microsoft's official Azure-Sentinel Detections (MIT licensed).)",
        "query": "let threatCategory=\"Powershell\";\nlet knownUserAgentsIndicators = materialize(externaldata(UserAgent:string, Category:string)\n    [ @\"https://raw.githubusercontent.com/Azure/Azure-Sentinel/master/Sample%20Data/Feeds/UnusualUserAgents.csv\"]\n        with(format=\"csv\", ignoreFirstRecord=True));\nlet knownUserAgents=toscalar(knownUserAgentsIndicators | where Category==threatCategory | where isnotempty(UserAgent) | summarize make_list(UserAgent));\nlet customUserAgents=toscalar(_GetWatchlist(\"UnusualUserAgents\") | where SearchKey==threatCategory | extend UserAgent=column_ifexists(\"UserAgent\",\"\") | where isnotempty(UserAgent) | summarize make_list(UserAgent));\nlet fullUAList = array_concat(knownUserAgents,customUserAgents);\n_Im_WebSession(httpuseragent_has_any=fullUAList)\n| project SrcIpAddr, Url, TimeGenerated, HttpUserAgent, SrcUsername\n| extend AccountName = tostring(split(SrcUsername, \"@\")[0]), AccountUPNSuffix = tostring(split(SrcUsername, \"@\")[1])"
      },
      {
        "name": "b12b3dab-d973-45af-b07e-e29bb34d8db9 — Cisco Cloud Security - Windows PowerShell User-Agent Detected",
        "description": "Rule helps to detect Powershell user-agent activity by an unusual process other than a web browser.' (Source: Microsoft's official Azure-Sentinel Detections (MIT licensed).)",
        "query": "Cisco_Umbrella\n| where EventType == \"proxylogs\"\n| where HttpUserAgentOriginal contains \"WindowsPowerShell\"\n| extend Message = \"Windows PowerShell User Agent\"\n| project TimeGenerated, Message, SrcIpAddr, DstIpAddr, UrlOriginal, HttpUserAgentOriginal"
      },
      {
        "name": "fa0ab69c-7124-4f62-acdd-61017cf6ce89 — Excessive Blocked Traffic Events Generated by User",
        "description": "Creates an incident when a Symantec Endpoint Proection agent detects excessive amounts of blocked traffic generated by a single user.' (Source: Microsoft's official Azure-Sentinel Detections (MIT licensed).)",
        "query": "let threshold = 15;\nlet NoteableEvents = SymantecEndpointProtection\n| where LogType == \"Agent Traffic Logs\"\n| where Action =~ \"Blocked\"\n| summarize TotalBlockedEvents = count() by UserName\n| where TotalBlockedEvents > threshold;\nSymantecEndpointProtection\n| where LogType =~ \"Agent Traffic Logs\"\n| where Action =~ \"Blocked\"\n| join kind=inner (NoteableEvents) on UserName\n| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), Total = count() by UserName, RuleName, ServerName, LocalHostIpAddr, LocalPortNumber, TrafficDirection, RemoteHostIpAddr, RemotePortNumber, ApplicationName"
      }
    ],
    "spl": [],
    "esql": [
      {
        "name": "debff20a-46bc-4a4d-bae5-5cdd14222795 — Base16 or Base32 Encoding/Decoding Activity",
        "description": "(EQL) Base16 and Base32 are encoding schemes that convert binary data into text, making it easier to transmit and store. This rule monitors for Base16 or Base32 encoding and decoding activity on Linux systems. Attackers may use these encoding schemes to obfuscate malicious payloads, evade detection, and facilitate data exfiltration. (Source: Elastic's official detection-rules repository (Elastic License v2).)",
        "query": "process where host.os.type == \"linux\" and event.type == \"start\" and\nevent.action in (\"exec\", \"exec_event\", \"start\", \"ProcessRollup2\", \"executed\", \"process_started\") and\nprocess.name in (\"base16\", \"base32\", \"base32plain\", \"base32hex\") and\nnot process.args in (\"--help\", \"--version\")"
      }
    ]
  },
  "automation": {
    "safe": [
      "Add recommendation as Sentinel incident comment.",
      "Run enrichment queries.",
      "Create ServiceNow SecOps task."
    ],
    "approval_required": [
      "Contain or disable the affected host/account.",
      "Any change to production configuration."
    ]
  },
  "escalation_criteria": [
    "Data Encoding activity observed on a privileged account or critical system.",
    "Activity follows or precedes other suspicious behaviour in the same investigation.",
    "Automated triage cannot confidently rule out malicious intent."
  ],
  "false_positive_considerations": [
    "Legitimate administrative or maintenance activity matching this pattern.",
    "Approved security testing or red team exercise.",
    "Known benign software producing similar telemetry."
  ],
  "confluence": {
    "title": "T1132 - Data Encoding Response Guidance",
    "labels": [
      "mitre",
      "attack",
      "d3fend",
      "secops",
      "basyrix"
    ],
    "sections": [
      "summary",
      "d3fend_mappings",
      "investigation_steps",
      "response_actions",
      "queries",
      "automation",
      "escalation_criteria",
      "false_positive_considerations"
    ]
  }
}