Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c8afc6d4d6e1f525…

MALICIOUS

RTF / .DOC

18.6 KB
MD5: 98c3f1d28f1049327467f419e6e6770f SHA-1: 1a87ca165db633c227f7ff705ab031d433cacef7 SHA-256: c8afc6d4d6e1f5250fe957b5efdf4c8e8069f79bcfad2b90ee783a2cdbf3871a
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 critical heuristics related to Equation Editor vulnerabilities. The presence of \objupdate indicates that the embedded OLE object is designed to be automatically activated upon opening, leading to the exploitation of the Equation Editor. This is a common delivery mechanism for exploiting known vulnerabilities to achieve arbitrary code execution.

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_off00001920.bin
e3d58c74da01c00547ddaa13747ac74de4bad0395960d2fe618565f4de2126a2
rtf-objdata-decoded RTF \objdata at offset 0x1920 1623 bytes