Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 d2b1089658223d5b…

MALICIOUS

RTF / .DOC

50.5 KB First seen: 2023-09-04
MD5: 7e35f863ee7aace2f6d2d552a163b5c4 SHA-1: 1164d2b290f70bc267aacf949b32e8a9fa033c00 SHA-256: d2b1089658223d5b5bca579fbdf8b488adbc157b558b6b2c939b858f439c4821
140 Risk Score

Malware Insights

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

The sample is an RTF document that leverages the Equation Editor vulnerability, indicated by the RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics. The SE_ENABLE_LURE heuristic suggests the document contains text prompting the user to enable editing, a common social engineering tactic. The embedded OLE object data further supports the exploitation of embedded objects within the RTF structure.

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_off00002ada.bin
79ddbde6d9bb6453fe2429e19f77351dda099caeab20e27dcf84abc7478f21d7
rtf-objdata-decoded RTF \objdata at offset 0x2ADA 1849 bytes