ThreatFox: GCleaner IOCs

Hunt Hypothesis

This hunt targets adversary behavior involving the execution of known malicious indicators from the GCleaner campaign to identify potential compromise or lateral movement within the network. The SOC team should proactively search for these specific IOCs in Azure Sentinel because their high severity suggests an active threat that requires immediate validation and containment before it escalates into a broader incident.

IOC Summary

Malware Family: GCleaner Total IOCs: 3 IOC Types: md5_hash, sha256_hash, sha1_hash

Type	Value	Threat Type	First Seen	Confidence
md5_hash	`9449a051bb8d647541dd980b998baabd`	payload	2026-07-13	95%
sha256_hash	`937c16c2f853b605c2be68982a65109fcd5f2cdf704b9438cd254a38ff529b7f`	payload	2026-07-13	95%
sha1_hash	`83dd3427c1f594f93bdec864dca1a59377259012`	payload	2026-07-13	95%

KQL: Hash Hunt

// Hunt for files matching known malicious hashes
// Source: ThreatFox - GCleaner
let malicious_hashes = dynamic(["9449a051bb8d647541dd980b998baabd", "937c16c2f853b605c2be68982a65109fcd5f2cdf704b9438cd254a38ff529b7f", "83dd3427c1f594f93bdec864dca1a59377259012"]);
DeviceFileEvents
| where SHA256 in (malicious_hashes) or SHA1 in (malicious_hashes) or MD5 in (malicious_hashes)
| project Timestamp, DeviceName, FileName, FolderPath, SHA256, InitiatingProcessFileName
| order by Timestamp desc

Required Data Sources

Sentinel Table	Notes
`DeviceFileEvents`	Ensure this data connector is enabled

References

ThreatFox — GCleaner

False Positive Guidance

Here are specific false positive scenarios for the ThreatFox: GCleaner IOCs detection rule, tailored for an enterprise environment where legitimate administrative activities may mimic the behavior of the GCleaner tool or its associated infrastructure.

Scheduled Enterprise Backup and Cleanup Jobs
- Scenario: The organization utilizes a centralized backup solution (e.g., Veeam Backup & Replication or Commvault) that runs nightly maintenance scripts to purge old logs, temporary files, and orphaned snapshots from the file server. These scripts often invoke specific executable names or generate network traffic patterns (such as connecting to known GCleaner update servers for signature checks) that match the rule’s IOCs.
- Filter/Exclusion: Create a filter to exclude alerts where the source process is vbr.exe (Veeam), simagent.exe (Symantec), or specific PowerShell scripts located in the C:\ProgramData\BackupJobs\Scripts directory, provided they are running during the defined maintenance window (e.g., 02:00 – 04:00 UTC).
Endpoint Management and Patching Deployments
- Scenario: The IT Operations team uses Microsoft Endpoint Configuration Manager (MECM/SCCM) or Ivanti Neurons to deploy a new security patch or agent update. During the deployment, these tools download installer packages from internal distribution points that host GCleaner binaries for testing. The network traffic generated by the SCCM client (ccmexec.exe) communicating with the distribution point may trigger the IOC associated with GCleaner’s command-and-control communication.
- Filter/Exclusion: Exclude events originating from the CCMExec service account or processes running under the System context where the destination IP belongs to the internal “Patch Distribution” subnet (e.g., `10.20