Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6593a33fa607b392…

MALICIOUS

RTF / .DOC

22.2 KB First seen: 2022-11-07
MD5: fdc12c34e283922cad675f74d28258b2 SHA-1: 9f7ed9b60d8ac6b53c073b5832fa652faa8d3bdf SHA-256: 6593a33fa607b3926e1f50c3d3f9bef6becfe7703a65acfe2560e587cbb055d6
140 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 sample is an RTF document that contains an embedded OLE object, specifically targeting the Equation Editor vulnerability. The `RTF_OBJUPDATE` heuristic indicates that the object is set to automatically activate, which, combined with the `SE_ENABLE_LURE` heuristic, suggests the document is designed to trick the user into enabling content to trigger the exploit. This exploit likely leads to the execution of a second-stage 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_off0000419d.bin
2a70a68e9d4d11029660f7e1c0bee784002c7f981c04329f0a96754d63bdbd59
rtf-objdata-decoded RTF \objdata at offset 0x419D 1695 bytes