Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 57872e73fbe04d57…

MALICIOUS

RTF / .DOC

4.5 KB First seen: 2022-03-29
MD5: a9d338770a177d3cecb3e8481b7deebe SHA-1: 9ad0767f4ce00ea7dd628914c76731aaa029f85f SHA-256: 57872e73fbe04d577949d86771f47ed10f90b4186e8f9ebb5195e74e485a80bf
121 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF document contains embedded OLE object data, specifically triggering the Equation Editor vulnerability. The \objupdate directive indicates that the embedded object will be automatically activated upon opening the document, leading to exploitation. This is a common delivery mechanism for exploiting client-side vulnerabilities to achieve arbitrary code execution.

Heuristics 3

  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000000dd.bin
c9db518aa29b2a0b345a94460dffbbf519e681e703e1c72a0c7432162c564a54
rtf-objdata-decoded RTF \objdata at offset 0xDD 2006 bytes