# T1087 - Account Discovery

## SOC Recommendation
Investigate Account 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 |
|---|---|---|
| Local Account Monitoring | Detect | Monitor for Local Account Monitoring indicators relevant to this technique. |
| Agent Authentication | Harden | Apply Agent Authentication to reduce this technique's viability before an incident occurs. |
| Account Locking | Evict | Use Account Locking to remove the adversary's foothold once this technique is confirmed. |
| User Account Permissions | Isolate | Apply User Account 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 |
|---|---|---|---|
| Contain the affected host or account | Medium | No | Yes |
| Collect and preserve evidence | Low | Yes | No |

## KQL
```kql
let ReconTools = dynamic([
    "adfind.exe",
    "dsquery.exe",
    "sharphound.exe",
    "bloodhound.exe"
]);
let ReconCommandPatterns = dynamic([
    "Get-DomainUser",
    "Get-DomainGroup",
    "Get-DomainTrust",
    "Get-NetUser",
    "Get-NetGroup",
    "Invoke-BloodHound"
]);
DeviceProcessEvents
| where TimeGenerated >= ago(1d)
| where FileName in~ (ReconTools) or ProcessCommandLine has_any (ReconCommandPatterns)
| project
    TimeGenerated,
    DeviceName,
    DeviceId,
    AccountName,
    FileName,
    ProcessCommandLine,
    InitiatingProcessFileName,
    InitiatingProcessCommandLine
| extend timestamp = TimeGenerated,
         HostCustomEntity = DeviceName,
         AccountCustomEntity = AccountName
| order by TimeGenerated desc
```
```kql
let firstRec = FortyTwoCrunchAPIProtection
| where TimeGenerated >= ago(5m) 
| project-away NonBlockingMode, SourcePort, DestinationPort, Query, ApiId, RequestHeader, ResponseHeader, Errors, EventType, Uuid
| where (UriPath has "/api/register" or UriPath has "/api/reset") and Status == 403;
let recCount = iff((toscalar(firstRec | count) >= 20), 1, 0);
firstRec | take recCount
```
```kql
let args = dynamic(["objectcategory","domainlist","dcmodes","adinfo","trustdmp","computers_pwdnotreqd","Domain Admins", "objectcategory=person", "objectcategory=computer", "objectcategory=*","dclist"]);
let parentProcesses = dynamic(["pwsh.exe","powershell.exe","cmd.exe"]);
DeviceProcessEvents
//looks for execution from a shell
| where InitiatingProcessFileName in~ (parentProcesses)
// main filter
| where FileName =~ "AdFind.exe" or SHA256 == "c92c158d7c37fea795114fa6491fe5f145ad2f8c08776b18ae79db811e8e36a3"
   // AdFind common Flags to check for from various threat actor TTPs
    or ProcessCommandLine has_any (args)
| extend HostName = split(DeviceName, '.', 0)[0], DnsDomain = strcat_array(array_slice(split(DeviceName, '.'), 1, -1), '.'), FileHashAlgorithm = "SHA256"
```

## Escalation Criteria
- Account 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.