Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 803a79308ca5ccc5…

MALICIOUS

RTF / .DOC

52.1 KB First seen: 2023-10-09
MD5: 25626aada7692edd85af0b185f67fdb0 SHA-1: bb9f3a99dde0a24f3f29dae4724f44c60fc7fdb7 SHA-256: 803a79308ca5ccc55de57681af885b884ad9dbb93ce0771ade0932b2be8a5ab0
180 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 exploits the Equation Editor vulnerability. It contains OLE object data and an automatically linked OLE object that forces activation via \objupdate. The document body provides a lure to enable editing, which is a common technique for macro-based malware droppers to bypass security settings and execute a secondary payload.

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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off00002d84.bin
39aaf5df5e93647172c73c8aebdb247464decf44b00d37fc6729a94f684e3839
rtf-objdata-decoded RTF \objdata at offset 0x2D84 1345 bytes