# T1036 - Masquerading

## SOC Recommendation
Investigate Masquerading activity in the context of Stealth: 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 |
|---|---|---|
| System Call Analysis | Detect | Monitor for System Call Analysis indicators relevant to this technique. |
| File Encryption | Harden | Apply File Encryption to reduce this technique's viability before an incident occurs. |
| File Eviction | Evict | Use File Eviction to remove the adversary's foothold once this technique is confirmed. |
| System Call Filtering | Isolate | Apply System Call 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 |
|---|---|---|---|
| Kill the masquerading process via MDE Live Response | Low | No | Yes |
| Delete the malicious binary | Low | No | Yes |
| Block SHA256 in MDE custom indicators | Medium | No | Yes |

## KQL
```kql
let LegitPaths = dynamic([
    "c:\\windows\\system32\\", "c:\\windows\\syswow64\\",
    "c:\\windows\\", "c:\\program files\\", "c:\\program files (x86)\\"
]);
let SystemBinaries = dynamic([
    "svchost.exe", "lsass.exe", "services.exe", "csrss.exe", "winlogon.exe",
    "wininit.exe", "explorer.exe", "taskhostw.exe", "taskhost.exe", "spoolsv.exe",
    "dllhost.exe", "mmc.exe", "searchindexer.exe", "lsm.exe", "smss.exe", "conhost.exe"
]);
DeviceProcessEvents
| where TimeGenerated >= ago(5m)
| where FileName in~ (SystemBinaries)
| where isnotempty(FolderPath)
| where not(FolderPath has_any (LegitPaths))
| project
    TimeGenerated,
    DeviceName,
    AccountName,
    FileName,
    FolderPath,
    ProcessCommandLine,
    SHA256,
    InitiatingProcessFileName
| extend timestamp = TimeGenerated,
         HostCustomEntity = DeviceName,
         AccountCustomEntity = AccountName
| order by TimeGenerated desc
```
```kql
let lb_period = 14d;
let q_time = 1h;
let inet_access_proc = CyberArkEPM
| where TimeGenerated between (ago(lb_period) .. ago(q_time))
| where EventSubType =~ 'DetectAccessInternet'
| where isnotempty(ActingProcessFileInternalName)
| summarize makeset(ActingProcessFileInternalName);
CyberArkEPM
| where TimeGenerated > ago(q_time)
| where EventSubType =~ 'DetectAccessInternet'
| where ActingProcessFileInternalName !in (inet_access_proc)
| extend AccountCustomEntity = ActorUsername
```
```kql
CyberArkEPM
| where EventSubType != 'AttackAttempt'
| where ActingProcessName has @'\'
| where ActingProcessName !has ActingProcessFileInternalName
| project EventEndTime, EventMessage, ActorUsername, ActingProcessFileInternalName
| extend AccountCustomEntity = ActorUsername
```

## Escalation Criteria
- Masquerading 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.