Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 83070bfdf52c5e29…

MALICIOUS

RTF / .DOC

932.8 KB
MD5: 4bf5eb945b746e3302857ac20d02856e SHA-1: 9b97f8e3aa48df50ab06bd4d7587835bb5dd7c36 SHA-256: 83070bfdf52c5e298e4c395e89eae025901ba6c4eab56f474fd79f7721e58750
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 with decoded Equation Editor payload, indicating an exploit targeting this component. The \objupdate heuristic suggests the exploit is designed to activate automatically. The extracted objdata artifact is likely the dropped malicious payload, which is expected to download and execute a second-stage payload.

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
ef431a761fbc962eda97aa3a629ef43fe76002ac4b1acec20a2e988caa10910c
rtf-objdata-decoded RTF \objdata at offset 0x43 477461 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.