Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 309fa7a49ec51591…

MALICIOUS

RTF / .DOC

155.7 KB First seen: 2024-05-21
MD5: f0b81727aaae72dd97b0420c46427ac2 SHA-1: ae2806f7a923214a0e82f7a788f14a269a236315 SHA-256: 309fa7a49ec515910ccb0d8432e1bcc2bb7d9f8c252230177236e0a028488377
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 sample is an RTF document that leverages an Equation Editor vulnerability, indicated by the RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics. The document body contains a lure related to financial audits, instructing the user to 'enable editing', which is a common tactic to bypass macro security. The presence of OLE object data suggests the embedded object is intended to be activated, likely to exploit the Equation Editor vulnerability and execute a 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_off00008e6d.bin
b8cc59917d197eecbfb98475bfa3e0a59883392e5614a4cb41fc24293bea2404
rtf-objdata-decoded RTF \objdata at offset 0x8E6D 1960 bytes