Buzus — RTF / .DOC malware analysis

Static analysis result for SHA-256 ca052646024901b0…

MALICIOUS

RTF / .DOC

73.0 KB Authoring application: Msftedit 5.41.15.1515
MD5: c7069f8fa313e9c4fde373acd0df296e SHA-1: caf68cc18297b3acd30b828e76867cedd3ff039d SHA-256: ca052646024901b0ae214c9b4b67996deac663b1cb5d8a78a3898f638860ba9b
262 Risk Score

Malware Insights

Buzus · confidence 95%

MITRE ATT&CK
T1559.001 Component Object Model Hijacking T1204.002 Malicious File

The RTF file contains an embedded OLE object, identified as a package object. Static analysis reveals a PE header within this object's data, indicating it is likely an executable. ClamAV signatures confirm this, detecting it as Win.Trojan.Buzus-7479. The primary attack pattern involves leveraging OLE object embedding to deliver a malicious payload.

Heuristics 7

  • 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.Buzus-7479 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Buzus-7479
  • 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
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000000d1.bin
23e311290e3a0fe7e4beb258aeea55fc2c9c2d269d277e71b569854d2bc6ccbc
rtf-objdata-decoded RTF \objdata at offset 0xD1 33039 bytes
Detection
ClamAV: Win.Trojan.Buzus-7479
Obfuscation or payload: likely
Carved artifact entropy is 7.47, consistent with packed or encrypted content.