Malicious RTF — malware analysis report

Static analysis result for SHA-256 314ebae4b7fc2a46…

MALICIOUS

RTF

46.0 KB First seen: 2023-07-18
MD5: 86c6b589396bd7069c39b4dc6578b1ad SHA-1: f74ab2fadf5bd8b3ceed9cb2909f1920435d414f SHA-256: 314ebae4b7fc2a469b7de3aea6246db22cc31f2e7ee443b6126cee0b8a10566a
160 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 and specifically triggers the RTF_EQUATION_EDITOR heuristic, indicating a likely exploit targeting the Microsoft Equation Editor. The document body includes a lure instructing the user to 'Enable editing', which is a common tactic to bypass macro security and activate embedded exploits. The presence of ".objupdate" further suggests an attempt to force OLE activation, likely to trigger the 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_off00005270.bin
c7bdb1e43c2ad8983badb43522344c4bc3f65361f2e229dc4ebf89fd25dd4ef4
rtf-objdata-decoded RTF \objdata at offset 0x5270 2048 bytes