Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ad4a9f03995ef8fa…

MALICIOUS

RTF / .DOC

982.8 KB First seen: 2023-10-22
MD5: 58bbfc3f4971c44d3efb60e97299a5a5 SHA-1: a487e3cbcc857afa70a3549c7820a4c75acb5c92 SHA-256: ad4a9f03995ef8fa50027c10e69e9e8a814f21e89f1019f482ba8b859e079c68
102 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1027 Obfuscated Files or Information

The RTF document contains a large OLE object with excessive hex-encoded data, flagged as suspicious. Heuristics indicate that \objupdate forces OLE activation, suggesting an attempt to execute embedded content. The extracted artifact 'objdata_00_off00000089.bin' is likely the hidden payload.

Heuristics 4

  • \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.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~1006KB of hex-encoded data inside \objdata sections — may hide a payload
  • 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_off00000089.bin
9e59c2cc2b25086cfb8c263216449b0e56f0ac46b4faea1b73dd1d2ac3939533
rtf-objdata-decoded RTF \objdata at offset 0x89 503082 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.