Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 b9a2ff579d96535b…

MALICIOUS

RTF / .DOC

312.0 KB
MD5: cd6bc53b63274cdfc9242ff5966822bb SHA-1: a14ed34a344f27ad3997ad1a511ff95bec141cc7 SHA-256: b9a2ff579d96535b739483b729aa2fbd7f9905b9c11163a1e331a6b2a8ad0daf
122 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF file contains an embedded OLE object that decodes to a PE file, leveraging the Equation Editor vulnerability. The ".objupdate" heuristic indicates that the OLE object is designed to be activated automatically. The extracted artifact "objdata_00_off0000174d.bin" is the decoded payload, likely a downloader or dropper.

Heuristics 4

  • Decoded Equation Editor payload + PE critical RTF_EQUATION_EDITOR
    RTF decodes to an Equation Editor ProgID adjacent to OLE activation and the same decoded object stream contains embedded PE bytes. This matches the Equation Editor exploit surface used by CVE-2017-11882 / CVE-2018-0802 documents, while requiring payload evidence to avoid flagging benign Equation references.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects
  • 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_off0000174d.bin
6cdb8de3ae4164d116605818ca747741a06d219647e9a9b9b69191aeb9b3ef1d
rtf-objdata-decoded RTF \objdata at offset 0x174D 156699 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.