Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 84ba740be46bc107…

MALICIOUS

RTF / .DOC

29.6 KB First seen: 2022-11-21
MD5: 9cf394d81764277fec3f8052efc7b53d SHA-1: 5b73bc81f5cd67a33409d7b6102ea7f3cd0d86f7 SHA-256: 84ba740be46bc107e042501999f4cfdc8f813bf18efdda30c59613f190a97c7e
140 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability (CVE-2017-11882). The presence of \objupdate further suggests that the OLE object is designed to be activated automatically. The document body contains a lure instructing the user to 'Enable editing', which is a common tactic to bypass macro security settings and facilitate the exploitation of embedded objects. The primary goal appears to be the execution of a second-stage payload via the Equation Editor exploit.

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_off00005911.bin
749ca54a68eccfe16f86280ce37a16f55cbb51c339d71a918ca9d03d19fe94bd
rtf-objdata-decoded RTF \objdata at offset 0x5911 1633 bytes