Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 50f0fe86394abe91…

MALICIOUS

RTF / .DOC

26.6 KB First seen: 2022-11-16
MD5: afa6f535d53f097fa00ca3950ec31cd9 SHA-1: fcbcf0fd8294aa0a0727a2f195e26c6713c5d13f SHA-256: 50f0fe86394abe9174b74363b2e520be0dffb8baa477c7d752a6deef0fb9ce78
140 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object that exploits the Equation Editor vulnerability. The document body contains a lure instructing the user to 'Enable editing', which is a common technique to bypass macro security settings and trigger the exploit. The exploit likely leads to the execution of a second-stage payload.

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_off00004bd8.bin
cbb9f320c809453f963fa70ce1406c0be82b66386f20587fe1068d9d6c4d511b
rtf-objdata-decoded RTF \objdata at offset 0x4BD8 1714 bytes