Win.Trojan.Koobface-884 — RTF / .DOC malware analysis

Static analysis result for SHA-256 6c2e16960da121f5…

MALICIOUS

RTF / .DOC

85.3 KB Authoring application: Msftedit 5.41.15.1515
MD5: f916bf8f07a1d1e39ce745c3bd099842 SHA-1: 976ffbb6de28a440459ab7e4b26cffede9be5760 SHA-256: 6c2e16960da121f5f883ed4c173f99e1de037ed3a82cc9e608b37024c686ae76
260 Risk Score

Malware Insights

Win.Trojan.Koobface-884 · confidence 95%

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The RTF file contains an embedded OLE object which is identified as a PE executable by ClamAV. The presence of RTF_MZ_HEX and RTF_OBJCLASS_PACKAGE heuristics further indicates a malicious executable embedded within the document. This suggests the file is likely a malicious attachment designed to trick the user into executing a payload.

Heuristics 6

  • PE header (with DOS stub) in hex data critical RTF_MZ_HEX
    Hex-encoded PE (MZ + DOS stub) found inside RTF — likely an embedded executable payload
  • ClamAV: Win.Trojan.Koobface-884 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Koobface-884
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Package object class high RTF_OBJCLASS_PACKAGE
    OLE Package object — can wrap arbitrary files
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000000cf.bin
9a6511a15601a990c4ebf6b3e2d848dc2619aa332fe78cdb2cb42a960a29d789
rtf-objdata-decoded RTF \objdata at offset 0xCF 38703 bytes
Detection
ClamAV: Win.Trojan.Koobface-884
Obfuscation or payload: unlikely