Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 321ab0b1df215447…

MALICIOUS

RTF / .DOC

36.7 KB First seen: 2023-05-09
MD5: 0c9d9af32baccc096ae26ca80b67f7f1 SHA-1: 20312a7cbf860d29cf39f5f9a00916689e61bb9f SHA-256: 321ab0b1df215447186a761b854ed239113af908ddcd40740f2b8d539530ad49
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059.005 PowerShell T1204.002 User Execution: Malicious File

The RTF document contains an embedded OLE object and specifically triggers the RTF_EQUATION_EDITOR heuristic, indicating a likely exploit targeting the Microsoft Equation Editor component. The document also contains a lure instructing the user to 'Enable editing', a common tactic to bypass security measures and trigger the exploit. The embedded OLE object is likely a secondary payload or exploit.

Heuristics 5

  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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_off00004735.bin
28b2695276bd1f5669f661610674a53207214e339a7533780f8648abf994a00d
rtf-objdata-decoded RTF \objdata at offset 0x4735 1735 bytes