Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 a37993a8b65937a8…

MALICIOUS

RTF / .DOC

82.9 KB First seen: 2023-09-12
MD5: 0941b91094b603bf8b38e35179225e00 SHA-1: 48f47736a93792c01a45cefc90b06eead6e19952 SHA-256: a37993a8b65937a8775f8c88f47d98e889af083ac849c4367ae1de24151dec7c
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 file is an RTF document that leverages the Equation Editor vulnerability, indicated by the RTF_EQUATION_EDITOR heuristic. The document body contains text designed to trick the user into enabling editing and macros, a common lure for malware droppers. The presence of OLE object data and the objupdate directive further suggest that the document is intended to activate and execute embedded malicious 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_off00004223.bin
ab60bfaae33dffaf92063001ef67a087c4257abe03d55a45f58dcf7d3f161e62
rtf-objdata-decoded RTF \objdata at offset 0x4223 1513 bytes