Malicious RTF — malware analysis report

Static analysis result for SHA-256 741f2c4f96103460…

MALICIOUS

RTF

27.1 KB First seen: 2023-07-05
MD5: 4ba517cee0b4e4c77e6178a1f77d862b SHA-1: 1b5bb3efa1bb347352dc7bceae7bb55b0819eb91 SHA-256: 741f2c4f961034604f560c89ada5369e772eac51def7ebd6b4ac7840f8d0562e
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1059 Command and Scripting Interpreter T1059.005 Command and Scripting Interpreter: Visual Basic

The RTF document contains an embedded OLE object with data indicative of the Equation Editor vulnerability. The \objupdate directive suggests that the object will be activated automatically upon opening, bypassing user interaction. The document body contains a lure instructing the user to 'Enable editing', a common tactic to bypass macro security settings and trigger the exploit.

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_off0000458c.bin
2e5e22ac02695c3753846ae8844278fd9c1f2b4c0f0d9df3dbc383dd5d9ce656
rtf-objdata-decoded RTF \objdata at offset 0x458C 1691 bytes