Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 50c4fee0134f3238…

MALICIOUS

RTF / .DOC

42.4 KB First seen: 2023-02-18
MD5: 883024ca315da7998a6eba20ae6055d0 SHA-1: 23f60a5c61dbf2d7392dff25bbb614eaba929196 SHA-256: 50c4fee0134f3238bc0c99b60a4418cd2b853ce3a68bb010b950563d686b38fd
140 Risk Score

Malware Insights

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

The RTF document contains OLE object data and specifically targets the Equation Editor vulnerability (RTF_EQUATION_EDITOR). The presence of \objupdate indicates an attempt to automatically activate the embedded object, likely to trigger the exploit. The document body contains a lure instructing the user to 'Enable editing', a common tactic for macro-based malware.

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_off00005958.bin
617ca8d42b90403b5a16f9df293fa87fd80a9beba7d5775399902e6c63fc45be
rtf-objdata-decoded RTF \objdata at offset 0x5958 1702 bytes