Malicious RTF — malware analysis report

Static analysis result for SHA-256 248c1f8f88ecec7e…

MALICIOUS

RTF

41.0 KB First seen: 2023-07-10
MD5: f70ea388df8d91130be430d51301f8e1 SHA-1: 2d577d7e8893549691ab2f9fc6163b677825e725 SHA-256: 248c1f8f88ecec7e687789ef11c99db2a74ad89c4e8c691ce35d91798156ef60
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059.005 Visual Basic T1204.002 Malicious File

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability. The presence of \objupdate suggests that the OLE object is configured to activate automatically upon opening. The document body includes a lure instructing the user to 'Enable editing', a common tactic to bypass macro security and trigger the exploit. The exploit likely leads to the download and execution of a secondary payload.

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_off000050b4.bin
de1a710e5e6ee82f1cd639fd224d40094c788bb4c09ca7c001e110261dc1d286
rtf-objdata-decoded RTF \objdata at offset 0x50B4 1719 bytes