# T1018 - Remote System Discovery

## SOC Recommendation
Investigate Remote System 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 |
|---|---|---|
| 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 |
|---|---|---|---|
| Contain the affected host or account | Medium | No | Yes |
| Collect and preserve evidence | Low | Yes | No |

## KQL
```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"]);
imProcessCreate
//looks for execution from a shell
| where ActingProcessName has_any (parentProcesses)
| extend ActingProcessFileName = tostring(split(ActingProcessName, '\\')[-1])
| where ActingProcessFileName in~ (parentProcesses)
// main filter
| where Process hassuffix "AdFind.exe" or TargetProcessSHA256 == "c92c158d7c37fea795114fa6491fe5f145ad2f8c08776b18ae79db811e8e36a3"
// AdFind common Flags to check for from various threat actor TTPs
or CommandLine has_any (args)
| extend AlgorithmType = "SHA256"
| extend AccountName = tostring(split(User, @'\')[1]), AccountNTDomain = tostring(split(User, @'\')[0])
| extend HostName = tostring(split(Dvc, ".")[0]), DomainIndex = toint(indexof(Dvc, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Dvc, DomainIndex + 1), Dvc)
| project-away DomainIndex
```
```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"
```
```kql
ClarotyEvent
  | where EventOriginalType has 'Policy Violation' or EventType has 'Policy Violation'
  | project TimeGenerated, DstIpAddr, EventOriginalType, EventType
  | extend IPCustomEntity = DstIpAddr
```

## Escalation Criteria
- Remote System 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.