Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 46a37d515e977e6f…

MALICIOUS

RTF / .DOC

22.7 KB
MD5: 3c6cab492dea95ef7cbfa9dedd25798c SHA-1: fb3396c12d0041333b054fa45d2a2e8b59fd791c SHA-256: 46a37d515e977e6f0a78ea9c2cfdaf9c208ef8d2f61f1bd1a196f54fc0ecdaed
180 Risk Score

Malware Insights

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

The RTF document contains embedded OLE object data, specifically triggering heuristics related to the Equation Editor vulnerability (CVE-2017-11882). The presence of \objupdate further indicates an attempt to force OLE object activation. This strongly suggests the document is designed to exploit this known vulnerability to achieve arbitrary code execution.

Heuristics 5

  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \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 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000011b9.bin
f4b962e5f1b710587724e1c5ce0cadf1df05061cb18375d04e057466f2e2a03e
rtf-objdata-decoded RTF \objdata at offset 0x11B9 1764 bytes