ThreatFox: MacSync IOCs

Hunt Hypothesis

This hypothesis targets the presence of MacSync backdoor indicators, which facilitate remote command execution and data exfiltration through compromised domains and stolen credentials. Proactively hunting for these IOCs in Azure Sentinel allows the SOC team to identify early-stage infections and lateral movement attempts before the adversary establishes persistent access or exfiltrates sensitive data.

IOC Summary

Malware Family: MacSync Total IOCs: 6 IOC Types: domain, sha256_hash, url

KQL: Domain Hunt

// Hunt for DNS queries to known malicious domains
// Source: ThreatFox - MacSync
let malicious_domains = dynamic(["yoauction.com", "zanderrealestate.com"]);
DnsEvents
| where Name has_any (malicious_domains)
| project TimeGenerated, Computer, Name, IPAddresses, QueryType
| order by TimeGenerated desc

KQL: Url Hunt

// Hunt for access to known malicious URLs
// Source: ThreatFox - MacSync
let malicious_urls = dynamic(["https://zanderrealestate.com/curl/85cb26206d920216eee0c5f67e8de516b4d55bd1752025bb3c08a069a44fdbdf", "https://yoauction.com/curl/b42a0ed9d1ecb72e42d6034502c304845d98805481d99cea4e259359f9ab206e"]);
UrlClickEvents
| where Url has_any (malicious_urls)
| project Timestamp, AccountUpn, Url, ActionType, IsClickedThrough
| order by Timestamp desc

KQL: Hash Hunt

// Hunt for files matching known malicious hashes
// Source: ThreatFox - MacSync
let malicious_hashes = dynamic(["fbc460f7b29d7e709c28fc9368a592f3140fdb51fff5de54471450e250b6345a", "25ce426b8b075dee1d250a417423b60d55c572a8b38641d919d87b83c4ea6edd"]);
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

References

• ThreatFox — MacSync

False Positive Guidance

• Legitimate Sync Service Usage: Employees or IT administrators may use legitimate cloud synchronization tools (e.g., Dropbox, OneDrive, or custom internal sync scripts) that establish persistent outbound connections to known domains. If the MacSync IOCs include generic sync endpoints or specific IP ranges, these legitimate services could trigger alerts.
  • Filter/Exclusion: Exclude known internal sync service hostnames (e.g., sync.corp.example.com) or specific service accounts used for automated file syncing from the detection logic.
• Scheduled Backup Jobs: Enterprise backup solutions (e.g., Veeam, Commvault, or Acronis) often run scheduled jobs that connect to external storage or update servers. If the malware’s exfiltration channels mimic standard backup protocol ports or domains, these routine jobs may be flagged.
  • Filter/Exclusion: Create an exclusion for the specific service accounts or process names (e.g., vssadmin.exe, commvaultagent.exe) associated with the organization’s backup infrastructure, ensuring they are whitelisted for the specific IOCs (domains/IPs) involved.
• Development/Testing Environments: Developers in staging or QA environments may deploy test applications or containers that use mock APIs or temporary domains resembling those used by MacSync for command-and-control (C2). These environments often have looser network controls and may use dynamic DNS or cloud provider IPs that overlap with IOCs.
  • Filter/Exclusion: Exclude source IPs or subnets designated for development and testing (e.g., 10.20.0.0/24) or specific container hostnames (e.g., dev-node-01) from the detection rule, provided these environments are isolated from production networks.
• Third-Party SaaS Integrations: Some enterprise SaaS applications (e.g., Jira, Confluence, or internal portals) may