Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f21cff90e7d5d64d…

MALICIOUS

RTF / .DOC

28.9 KB First seen: 2022-11-11
MD5: c412632557b2f35079e09833eef16459 SHA-1: f9eb8c12a6fcad82c85c10ee2ec56c2bcb694fe3 SHA-256: f21cff90e7d5d64d476736baa7628870d23ffd64249bd34575acf3847187461d
140 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a specific focus on the Equation Editor, a known vector for exploits. The \objupdate directive further suggests an attempt to automatically activate this object upon opening. The document body includes a lure to 'Enable editing', which is a common tactic to bypass security measures and execute malicious content.

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_off00005b2e.bin
9eee82dae43e419b27c757d0f0652142d33834674da70c42aec0166910dc2386
rtf-objdata-decoded RTF \objdata at offset 0x5B2E 1752 bytes