# T1187 - Forced Authentication

## SOC Recommendation
Investigate Forced Authentication activity in the context of Credential Access: 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 |
|---|---|---|
| File Analysis | Detect | Monitor for File 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. |
| Content Filtering | Isolate | Apply Content 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 loginRec = FortyTwoCrunchAPIProtection
| where TimeGenerated >= ago(5m) 
| project-away NonBlockingMode, SourcePort, DestinationPort, Query, ApiId, RequestHeader, ResponseHeader, Errors, EventType, Uuid
| where UriPath has "/api/login?user=" and Status == 403;
let recCount = iff((toscalar(loginRec | count) > 10), 1, 0);
loginRec | take recCount
```
```kql
union corelight_conn, corelight_conn_red
| where local_orig == true
| where local_resp == false
| where history hasprefix 'Sh' and service hasprefix 'smb'
```
```kql
GCPCloudDNS
| where Query has_any ('autodiscover.com.br', 'autodiscover.com.cn', 'autodiscover.com.co', 'autodiscover.es', 'autodiscover.fr', 'autodiscover.in', 'autodiscover.it', 'autodiscover.sg', 'autodiscover.uk', 'autodiscover.xyz', 'autodiscover.online')
| extend DNSCustomEntity = Query, IPCustomEntity = SrcIpAddr
```

## Escalation Criteria
- Forced Authentication 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.