Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 91a88238f5b4dc93…

MALICIOUS

RTF / .DOC

300.0 KB
MD5: 4ba5af0ca862e168e6be9b311c19d023 SHA-1: 489c5f20f70391e817a1b2406f164b789094c376 SHA-256: 91a88238f5b4dc93a3626e9fc6cf1c5e10b5690153bac179606128380fb45142
142 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1204 User Execution

The RTF file contains an embedded OLE object that leverages the Equation Editor vulnerability. This exploit is designed to download and execute a secondary payload, as indicated by the critical RTF_EQUATION_EDITOR heuristic. The extracted artifact 'objdata_00_off00000043.bin' is likely the initial stage of this malicious chain.

Heuristics 5

  • 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
  • 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_off00000043.bin
aa560bc2be2555fb96a629af441bfdb249cc34c636b6a01e516bde004bb607cc
rtf-objdata-decoded RTF \objdata at offset 0x43 153445 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.