Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 20bd3c79d8c3bf50…

MALICIOUS

RTF / .DOC

4.0 KB
MD5: 0000fa000fdb3535678a7f363036fe22 SHA-1: 34c75801c6b3bdce8eca6dafe354eff687dc07a8 SHA-256: 20bd3c79d8c3bf501a857763054bdfd8cb1641dde194fe541a76a5d9fa1d3c1d
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF document contains OLE object data and specifically triggers the Equation Editor vulnerability. The ".bin" file extracted from the OLE object likely contains a secondary payload. The presence of RTF_OBJAUTLINK and RTF_OBJUPDATE heuristics indicates that the embedded OLE object is designed to be automatically activated upon opening the document, leading to code execution.

Heuristics 4

  • 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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000000a9.bin
1c0e19821bedd934b4078d4a8f8f18ce65bc256418b3c3fce23d7e852f919835
rtf-objdata-decoded RTF \objdata at offset 0xA9 1767 bytes