Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 36ed457b97226f1b…

MALICIOUS

RTF / .DOC

24.6 KB First seen: 2022-11-08
MD5: f9205c6bb1b139f2c1bef7ffb3035bb8 SHA-1: 87491e0c2f783687a925431d70e4a0e200f87ddb SHA-256: 36ed457b97226f1bb54c5572804bcd8cb13f58949de59ccba09bb814741300aa
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The file is an RTF document containing an embedded OLE object with a specific Equation Editor ProgID, triggering critical heuristics for Equation Editor exploitation. The \objupdate directive indicates an attempt to force OLE activation, which is a common method for exploiting this vulnerability. The document body contains a lure to 'Enable editing', further supporting its role as a malicious document designed to exploit users.

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.
  • \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
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00004a2a.bin
5122efe5dac8ad9ed673fdf938b406b21f69610261a9aee3bf97fccb9db5efe2
rtf-objdata-decoded RTF \objdata at offset 0x4A2A 1749 bytes