Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 38dc522bcaf6a838…

MALICIOUS

RTF / .DOC

87.6 KB First seen: 2023-10-24
MD5: 36df008f19abb088541ff5e86f3df1d0 SHA-1: 75d83d5fe5a379e94e51c870fae0d5b63dfa55b8 SHA-256: 38dc522bcaf6a838c2c5be057a716a08c7a3dc78f8aaad92188405d943151c01
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1059 Command and Scripting Interpreter T1059.005 Command and Scripting Interpreter: Visual Basic

The file 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 to bypass security measures and trigger the exploit. The presence of RTF_OBJDATA, RTF_EQUATION_EDITOR, and RTF_OBJUPDATE heuristics strongly indicates an attempt to exploit this known vulnerability.

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_off00002ad1.bin
e083079e91dd883c297683afa743fa2f0106f26f0774b957007d92de490952d0
rtf-objdata-decoded RTF \objdata at offset 0x2AD1 1660 bytes