Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ca39bbf693e4c760…

MALICIOUS

RTF / .DOC

17.2 KB
MD5: 3bcc9e1a9d4221383d5f72e05681f6cf SHA-1: 97b183cbccb0afa83ce0b05dc9b7bd85e9184ecf SHA-256: ca39bbf693e4c76087d5774e030c1e9d81246f07a0d701436f31354b9165e00e
160 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 objects, specifically leveraging the Equation Editor vulnerability. The presence of `RTF_EQUATION_EDITOR` and `RTF_OBJUPDATE` heuristics strongly indicates an attempt to exploit this known vulnerability. This technique is commonly used to deliver a second-stage payload, likely leading to arbitrary 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_off000009d9.bin
4f6b7cd632a6fdaa876b738a6ffe30a3d63cc1e022a17b4778b233c9f2d868f5
rtf-objdata-decoded RTF \objdata at offset 0x9D9 1975 bytes