Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 a8055f50ec6818f4…

MALICIOUS

RTF / .DOC

255.1 KB First seen: 2022-02-15
MD5: 247fa370920a748e856535eabe8f4083 SHA-1: 8386e615ee189ff4b65e19e9953b91b7d1aa41ce SHA-256: a8055f50ec6818f43e61200654fa29c6ce37e3ea631924a16e2ce0f9baadbbc3
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1559.001 Component Object Model Hijacking

The RTF document contains embedded OLE objects, specifically triggering critical heuristics related to Equation Editor exploitation. The presence of \objupdate indicates an attempt to force OLE object activation, leading to the execution of arbitrary code. This is a common technique for delivering malicious payloads.

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_off000000b9.bin
2b885f3b453253534e2d0473c051041ae622356277eda652113db37fa4085631
rtf-objdata-decoded RTF \objdata at offset 0xB9 81568 bytes