Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 bcc576f723d78d9a…

MALICIOUS

RTF / .DOC

423.8 KB
MD5: 3d571f6cb1624c16ba8f7dddb3de5951 SHA-1: e99165495d2ecf02ab783a6e9e59781a8cb9b128 SHA-256: bcc576f723d78d9aa3beeaf1dbe3bc75052c087d6dc684d7ab137ae5e22a21cb
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 a likely exploit. The ".objupdate" heuristic suggests that the OLE object is designed to be automatically activated upon opening the document. This points to a classic exploit delivery mechanism, likely via spearphishing, to achieve arbitrary code execution.

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_off00000054.bin
90015db65975c50279e7c74fb4de5dc55fd9d5b23a62fcfc13c43a65fdffbcdb
rtf-objdata-decoded RTF \objdata at offset 0x54 216864 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.