Techniques
Sample rules
Windows Unsigned DLL Side-Loading
- source: splunk
- technicques:
- T1574.002
Description
This analytic focuses on detecting potentially malicious unsigned DLLs created in either the c:\windows\system32 or c:\windows\syswow64 folders. This particular technique was observed in the context of the Warzone (Ave Maria) RAT, where it employed a method known as DLL hijacking (dll-side-loading) by dropping the “dismcore.dll” to achieve privilege escalation. DLL hijacking is a stealthy attack technique used by cybercriminals to exploit the way Windows searches and loads DLLs. By placing a malicious DLL with the same name as one that a legitimate application is expected to load, the attacker can gain unauthorized access and execute malicious code. In the case of Warzone RAT (Ave Maria), the dropped “dismcore.dll” was intended to deceive the system into loading the rogue DLL instead of the legitimate version, thereby granting the malware elevated privileges and enabling further compromise of the target system. Detecting such suspicious DLLs is crucial in preventing privilege escalation attacks and other potential security breaches. Regular security assessments, thorough monitoring, and implementing security best practices are essential in safeguarding systems from such threats.
Detection logic
`sysmon` EventCode=7 Signed=false OriginalFileName = "-" SignatureStatus="unavailable" ImageLoaded IN ("*:\\windows\\system32\\*", "*:\\windows\\syswow64\\*")
| stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded Signed SignatureStatus OriginalFileName process_name dest EventCode ProcessId Hashes IMPHASH
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_unsigned_dll_side_loading_filter`