Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 8ad456fc82b1c617…

MALICIOUS

RTF / .DOC

15.3 KB First seen: 2021-10-23
MD5: fc66be4a9696798aff0be8ed97bd294f SHA-1: cf158b670ec831531a233d41872d1a9ee3850ff1 SHA-256: 8ad456fc82b1c617f362b0356e6273ca6952368d3478f3f11c55e7c968158a15
120 Risk Score

Malware Insights

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

The sample is an RTF document containing OLE object data, specifically triggering critical heuristics for the Equation Editor vulnerability. The \objupdate directive indicates that the embedded OLE object will be activated upon opening, leading to the exploitation of the Equation Editor. This is a common delivery mechanism for exploiting client-side vulnerabilities to download and execute further 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_off000002fc.bin
4cc8fb3a77542539de9af008612d6160afca8fcb45908a42776b3a1bf5c24a41
rtf-objdata-decoded RTF \objdata at offset 0x2FC 1643 bytes