Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f6f109e285bd5038…

MALICIOUS

RTF / .DOC

60.3 KB First seen: 2023-10-11
MD5: 636a0d3559f741cefd1db17dc0a686be SHA-1: 90b41df4a5908ed58e19494dd4743d1c7dfda932 SHA-256: f6f109e285bd5038b106c75d522b145caef0ec4b0ec113f7cfbd75d7475030d8
160 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object and specifically targets the Equation Editor vulnerability, a known exploit vector. The presence of the 'SE_ENABLE_LURE' heuristic indicates the document prompts the user to enable editing, a common social engineering tactic to bypass security measures. This suggests the file is designed to exploit the Equation Editor to download and execute a malicious payload.

Heuristics 5

  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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_off00002c3d.bin
5ab030bd7a13a8fc65335359d735ed788a71916e161566347cec4a5d490eb614
rtf-objdata-decoded RTF \objdata at offset 0x2C3D 1520 bytes