Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 85a1052b20e76df4…

MALICIOUS

RTF / .DOC

520.4 KB
MD5: 3329da64e1856d4dff460464992c33cd SHA-1: 3188a4d27c2b9a8a0f18e6b7c72011480a386a48 SHA-256: 85a1052b20e76df4392c66e102d077b69999b89aec2a11b6787a6ba70cb58ebb
122 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF file contains embedded OLE object data, specifically a decoded Equation Editor payload. The ".\objupdate" heuristic indicates that the OLE object is designed to be activated automatically, triggering the embedded exploit. This strongly suggests the file is a malicious document designed to exploit the Equation Editor vulnerability to execute arbitrary code.

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_off00000043.bin
b01d4504412f69097b47a5aa352d8664f3847c733503b29baccf9938fa24e931
rtf-objdata-decoded RTF \objdata at offset 0x43 266337 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.