Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 4b9015eb413a5c39…

MALICIOUS

RTF / .DOC

47.7 KB First seen: 2023-04-21
MD5: f56b241fc782c9f48c07f4250fdc07ea SHA-1: 0f6fdab4d9906867867c278a52bc249cd243f710 SHA-256: 4b9015eb413a5c3900836fef95d16ff8b32e36a929851b42d037e79ddcf282b9
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, specifically targeting the Equation Editor vulnerability. The presence of the 'SE_ENABLE_LURE' heuristic indicates the document instructs the user to enable editing, which is a common technique to bypass security measures and trigger the exploit. The embedded OLE object and the specific Equation Editor heuristic strongly suggest an attempt to execute malicious code upon user interaction.

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_off0000523f.bin
9140a97dbf7d2ca6f2cc35bf728ab777e59c538b4f2a5020f0b0a0916cb6cc60
rtf-objdata-decoded RTF \objdata at offset 0x523F 1961 bytes