# T1083 - File and Directory Discovery

## SOC Recommendation
Investigate File and Directory Discovery activity in the context of Discovery: 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. |
| Local File Permissions | Isolate | Apply Local File Permissions 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 |
|---|---|---|---|
| If enumeration on a workstation (not a management server): i | Low | No | Yes |
| Review share permissions — are sensitive shares accessible t | Low | Yes | No |

## KQL
```kql
AWSCloudTrail
| where EventName == "DescribeImageScanFindings" and isempty(ErrorCode) and isempty(ErrorMessage)
| extend repoName = tostring(parse_json(ResponseElements).repositoryName)
| extend imageId = tostring(parse_json(ResponseElements).imageId.imageDigest)
| extend Critical = toint(parse_json(ResponseElements).imageScanFindings.findingSeverityCounts.CRITICAL)
| extend High = toint(parse_json(ResponseElements).imageScanFindings.findingSeverityCounts.HIGH)
| where Critical > 0 or High > 0
| extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
| extend UserName = tostring(split(UserIdentityArn, '/')[-1])
| extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
| extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
  AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")
```
```kql
Netclean_Incidents_CL |  where value_incidentVersion_d == 1
```
```kql
let discoveryRecords = FortyTwoCrunchAPIProtection
| where TimeGenerated >= ago(5m) 
| project-away NonBlockingMode, SourcePort, DestinationPort, Query, ApiId, RequestHeader, ResponseHeader, Errors, EventType, Uuid 
| where Status == 404 and ErrorMessage startswith "path not defined in OAS";
let discoveryCnt = (toscalar(discoveryRecords | count));
let recCount = iff((discoveryCnt > 500), 1, 0);
discoveryRecords | top recCount by Timestamp desc
```

## Escalation Criteria
- File and Directory Discovery 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.