Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 29f40b440f9ba83b…

MALICIOUS

RTF / .DOC

70.6 KB First seen: 2023-09-19
MD5: 47134ca4d7a6fc6a015113fc7db53b05 SHA-1: 10eac55afddc0120ff49d4cb9239f2d9110eaac8 SHA-256: 29f40b440f9ba83b9840828e3fadbcf22697008bb52befef98c834008da6616c
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059 Command and Scripting Interpreter

The RTF document contains an embedded OLE object and specifically triggers the RTF_EQUATION_EDITOR heuristic, indicating exploitation of a vulnerability within Microsoft Equation Editor. The document body contains a lure related to financial audits, instructing the user to 'Enable editing', which is a common tactic to bypass security measures and execute malicious code. The presence of objupdate further suggests an attempt to automatically activate the embedded object.

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_off0000326d.bin
20a1bc035d6057f4ceeed2d906743500778e8e8349e31c0fd232bbeb4c949935
rtf-objdata-decoded RTF \objdata at offset 0x326D 1676 bytes