Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 43bb28994e507931…

MALICIOUS

RTF / .DOC

36.1 KB First seen: 2023-02-02
MD5: 1505f7df9f58d4794b254887742340ad SHA-1: 9ef1ac90b7f0f83c0e13829ecb8ddca13f7cb2e8 SHA-256: 43bb28994e5079313633f892809a35ecd10770073a78cd3a6b028dd5ef42edd4
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, a known exploit technique. The \objupdate directive forces OLE activation, and the document body contains a lure instructing the user to 'Enable editing'. This combination strongly suggests an attempt to exploit a vulnerability, likely CVE-2017-11882, to execute a malicious payload.

Heuristics 4

  • 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 1 \objdata section(s) — embedded OLE objects
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00004b1a.bin
4022602f2ca46a796b1b815d5fb6b6e4870bef95ab6ddab3fff6ca0d0935eb3b
rtf-objdata-decoded RTF \objdata at offset 0x4B1A 1671 bytes