Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 8b5b4de9ef8c55bf…

MALICIOUS

RTF / .DOC

469.5 KB
MD5: 10033d73c17b6c6ac075fcb8c6069801 SHA-1: 6a722ca2bdd7bc28c53453cb60cd3b4e29343fa0 SHA-256: 8b5b4de9ef8c55bf65b0124427ee58f316a2e3c8a5e61565c71d5643c3194903
122 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with decoded Equation Editor payload, indicating a likely exploit. The ".objupdate" heuristic suggests that the embedded object is designed to be activated automatically, leading to the execution of the decoded Portable Executable (PE) file. This is a common delivery mechanism for malware.

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_off0000005e.bin
69fd9cc9fae0f85a37741f8318118ed40d16b29bfa6a151eaa4b44e08bbba396
rtf-objdata-decoded RTF \objdata at offset 0x5E 240275 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.