Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ca5f981a905f99b5…

MALICIOUS

RTF / .DOC

366.7 KB
MD5: cdf09dfcbf83167071e8732624f33043 SHA-1: c57af4cf698758dcb203806cba983bc9a75ab740 SHA-256: ca5f981a905f99b572dae3ee5cfc156f8ed827e45f582f1ac7198ba4f8a51062
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 leverages the Equation Editor vulnerability (RTF_EQUATION_EDITOR). The ".objupdate" heuristic indicates that the OLE object is designed to be activated automatically, likely to execute a malicious payload. The extracted file metadata and the critical heuristic strongly suggest this is a delivery mechanism for a secondary exploit or malware. No specific family could be identified.

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_off00000df7.bin
fa6ac99f8b9b6c01d7c62a54a7f3572b7e20767e0772385f286dd04654be9229
rtf-objdata-decoded RTF \objdata at offset 0xDF7 185905 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.