Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6b17b0af347d89c8…

MALICIOUS

RTF / .DOC

43.4 KB First seen: 2023-04-21
MD5: 14c31fd8c008c96358a9154f9751406e SHA-1: f49031150b588c448b6d5663404719da7670b542 SHA-256: 6b17b0af347d89c833d2eabe697bbd42b2b5741a628eaf43dcfcdba128df109e
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution

The sample is an RTF document that contains an embedded OLE object, specifically targeting the Equation Editor vulnerability. The document body includes a lure instructing the user to 'Enable editing', which is a common tactic for macro-based malware or exploits to bypass security warnings. The presence of RTF_OBJDATA, RTF_EQUATION_EDITOR, and RTF_OBJUPDATE heuristics strongly indicates an exploit attempt.

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_off00004bbb.bin
23f1416a5c263d67f9e941e475e5bdab3317a85e9634f5a3776023dd8a05b26a
rtf-objdata-decoded RTF \objdata at offset 0x4BBB 1970 bytes