Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 40ba454f4baf1370…

MALICIOUS

RTF / .DOC

31.5 KB First seen: 2023-01-10
MD5: 21b0f108a099754e1701da5a18f13ced SHA-1: 7400bcfa90fe05a43f0d28d49e022187ba572734 SHA-256: 40ba454f4baf1370b1891916313e0fe539a16bf2ef9eedc7982c758e2402ebbb
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059.005 PowerShell

The RTF document contains an OLE object with a split Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability. The presence of \objupdate suggests that the OLE object is designed to be activated automatically or upon user interaction, likely after the user clicks 'Enable editing' as prompted by the document body. This points to a classic exploit delivery mechanism aiming to execute a secondary payload.

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_off000045a3.bin
280d1ef8a423248028f5570894e42a1d815722ed0fa2274454d57d0447da0601
rtf-objdata-decoded RTF \objdata at offset 0x45A3 2040 bytes