Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 33c0a21926367514…

MALICIOUS

RTF / .DOC

58.5 KB
MD5: 6890bd33b210a9f974a5e9a0d5d139f0 SHA-1: 00732d0be1b50ffff2c6f50030d8ab3162397c20 SHA-256: 33c0a2192636751464430e0fd3155030f6f9dc3581b6271677c686e4c2176a02
120 Risk Score

Malware Insights

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

The file is an RTF document that leverages the Equation Editor vulnerability (CVE-2017-11882) to achieve code execution. The presence of \objdata and \objupdate directives strongly indicates the embedding and forced activation of an OLE object. This technique is commonly used to download and execute a secondary malicious payload. No specific family could be identified from the available heuristics.

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_off00001408.bin
b46d476d8999c81a63f2c519d09e28d0c3c456dea5d119275a946f3b36b13271
rtf-objdata-decoded RTF \objdata at offset 0x1408 1820 bytes