Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 92cc3a0ec27b8beb…

MALICIOUS

RTF / .DOC

3.4 KB First seen: 2022-04-09
MD5: 11ccfd6868a93a0bd8a88cc2e0476d2b SHA-1: 75b2b4f9baa257ca56e572251f0410cb94cd766f SHA-256: 92cc3a0ec27b8beb4229d687f5c0df4ec2bbde2abf85146a39fce9fbd9c2ac56
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF document contains embedded OLE objects, specifically triggering heuristics related to the Equation Editor vulnerability. The presence of \objupdate indicates that the embedded object is designed to be activated automatically upon opening, leading to the exploitation of the Equation Editor. This is a common delivery mechanism for malware.

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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off00000103.bin
f29ce1eb55faa2ffde0af081b31241dd056e84eeeecc7c8688916de645c0d8d5
rtf-objdata-decoded RTF \objdata at offset 0x103 1419 bytes