Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 3161d65e3a34ec9e…

MALICIOUS

RTF / .DOC

5.2 KB First seen: 2022-06-03
MD5: d50c8611d7f6c18e87778dd5120719c6 SHA-1: b6606076252cf1fc58c9ff407b867335238fd3c5 SHA-256: 3161d65e3a34ec9e83391432d2499a3c6d2090c46811163c10e45230fe3e2c2c
121 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.001 PowerShell

The RTF document contains embedded OLE object data and specifically triggers an Equation Editor exploit. The ".objupdate" directive forces the activation of this embedded object, leading to the execution of arbitrary code. This is a common technique for delivering malicious payloads via vulnerable document formats.

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_off00000081.bin
5e611777b7ec100a79504670b2e7953cace5f99de1c8d2444988be368d829e28
rtf-objdata-decoded RTF \objdata at offset 0x81 2279 bytes