Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c4922ae9cd82a5dd…

MALICIOUS

RTF / .DOC

75.0 KB First seen: 2023-08-07
MD5: 5cd62cdd2803e876f89378ddf6de3901 SHA-1: e81eb2ba26d93907a296eff4c243f16d77b3b5ca SHA-256: c4922ae9cd82a5ddbbaecf2c67d678b533610ba4dd3dc32d28bb8539d2963d6d
140 Risk Score

Malware Insights

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

The file is an RTF document containing an embedded OLE object that exploits a vulnerability in the Equation Editor. The document body includes a lure instructing the user to 'Enable editing', which is a common tactic to bypass macro security. The presence of RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics strongly suggests an attempt to execute malicious code via this vulnerability, likely leading to the download of a secondary 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_off000036f2.bin
0a7ebcedf1188933a5993db3b98529ffbba79fb560b326ae69d23ef80bc6619f
rtf-objdata-decoded RTF \objdata at offset 0x36F2 2071 bytes