Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 78a79e6a94f3a7ae…

MALICIOUS

RTF / .DOC

313.6 KB
MD5: fb46784bbd4e32cac1e3e3ce506a7531 SHA-1: 466cb86c16e509010c345f189f843e8093ceac31 SHA-256: 78a79e6a94f3a7aef005a06c9f9e804ca6089a9ce63f08d91ecd91227939b739
122 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell T1105 Ingress Tool Transfer

The RTF file contains an embedded OLE object that leverages the Equation Editor vulnerability. This vulnerability is known to be used for downloading and executing second-stage payloads. The heuristic firings strongly indicate the exploitation of the Equation Editor and the presence of a PE file within the OLE object, suggesting a downloader or initial access mechanism.

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_off00001e64.bin
8baeaf745946cc1b48711c7e54e5395131ac5d8b9a2a8a63947e36d34fa928ed
rtf-objdata-decoded RTF \objdata at offset 0x1E64 156461 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.