Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 39209507b110274d…

MALICIOUS

RTF / .DOC

391.5 KB
MD5: c50634f231931e767cb4a86f1f93c016 SHA-1: 4760ab4d74973b185d1c4176f78cc0565779cfd9 SHA-256: 39209507b110274dcee7dd049adc24b183d55182ea6ebaf0fc1fd8fb8b12c6dc
122 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object that leverages the Equation Editor vulnerability. This vulnerability is known to be used for delivering secondary payloads. The heuristic firings strongly indicate the exploitation of the Equation Editor to execute arbitrary code, likely leading to the download and execution of further malicious content.

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
c1cdb46cda89c5ad623516f3fd359adb2bfa372a3a616a4c0631158edbd2d20f
rtf-objdata-decoded RTF \objdata at offset 0x43 200309 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.