Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 9d144139dc61940b…

MALICIOUS

RTF / .DOC

91.2 KB First seen: 2023-10-23
MD5: f2299a90272e6c686f7926bf010d0956 SHA-1: d66d4eb626380ec825932d19dbd11bcc1eda9cce SHA-256: 9d144139dc61940b251e02233e416f9e7ccde1b6cc4b96978c1f88fb6c09f5d5
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File T1059 Command and Scripting Interpreter T1059.005 Visual Basic

The sample is an RTF document exploiting the Equation Editor vulnerability, indicated by the RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics. It contains an OLE object that is likely malicious, and the document body includes a lure to 'Enable editing' to bypass security measures. The SE_ENABLE_LURE heuristic confirms the presence of a social engineering tactic to trick the user into enabling content.

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_off000030a8.bin
c756b1591d446526a7b1f8b46dc389e676fbbb74bb2aa1cd02018488526f0901
rtf-objdata-decoded RTF \objdata at offset 0x30A8 1686 bytes