Hunt Hypothesis
This hypothesis targets the presence of Symantec Visual Cafe v30, a legacy development tool often exploited by adversaries to compile and execute malicious code or obfuscate payloads within the environment. Proactively hunting for this artifact in Azure Sentinel allows the SOC team to identify potential supply chain compromises or insider threats leveraging outdated software to establish a foothold or stage further malicious activities.
YARA Rule
rule Symantec_Visual_Cafe_v30_additional: PEiD
{
strings:
$a = { 53 FF 15 ?? ?? ?? 00 B3 22 38 18 74 03 80 C3 FE 8A 48 01 40 33 D2 3A CA 74 0A 3A CB 74 06 8A 48 01 40 EB F2 38 10 74 01 40 ?? ?? ?? ?? FF 15 }
condition:
$a at pe.entry_point
}
Deployment Notes
This YARA rule can be deployed in the following contexts:
- Microsoft Defender for Endpoint — Custom indicators / advanced hunting
- Email Gateway — Attachment scanning
- File Share Monitoring — Periodic scanning of shared drives
- YARA CLI — Manual threat hunting on endpoints
This rule contains 1 string patterns in its detection logic.
False Positive Guidance
- Legacy Application Deployment via Group Policy: Administrators deploying older, unmaintained internal line-of-business applications (e.g., legacy inventory management or point-of-sale systems) developed in Visual Cafe 3.0 may push executable files to endpoints via Group Policy Software Installation. These files often retain the original compiler metadata, triggering the YARA rule.
- Filter/Exclusion: Exclude files located in specific legacy application directories (e.g.,
C:\Program Files\LegacyApps\*) or exclude processes where the parent is gpupdate.exe or mstsc.exe during initial deployment windows.
- Scheduled Backup or Archive Jobs: Enterprise backup solutions or custom PowerShell scripts that archive old application binaries to network shares or local archive folders may copy Visual Cafe 3.0 executables without re-compiling them. If the YARA rule scans file systems or memory dumps of these archives, it will flag the static binaries.
- Filter/Exclusion: Exclude files with extensions like
.bak, .old, or .zip/.7z containers, or exclude paths under known backup directories (e.g., D:\Backups\, \\fileserver\archives\).
- Virtual Machine or Container Image Scanning: When security teams perform periodic integrity scans of golden images, VM templates, or container layers (e.g., Docker images used for CI/CD pipelines), the YARA rule may detect Visual Cafe 3.0 binaries embedded in older base images or legacy service containers.
- Filter/Exclusion: Exclude detections originating from virtual disk files (
.vhd, .vmdk, .qcow2) or container image layers (.tar, .layer) unless the rule is specifically designed to scan unpacked binaries.
- Development and QA Environments: Developers and QA engineers testing legacy code compatibility or running regression tests on older versions of applications