Malicious RTF — malware analysis report

Static analysis result for SHA-256 246762e0798d86fd…

MALICIOUS

RTF

29.9 KB First seen: 2023-05-30
MD5: 929bfc2d650dfa49c9a6133095ecf2fb SHA-1: 901402e4b34ec77b2deacb7c163de9003b5aab2b SHA-256: 246762e0798d86fd74e0aefed5675f04965f3918b32bdd22fb0f226bf11083b8
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.005 Service Execution

The RTF file contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability (CVE-2017-11882). The \objupdate directive further suggests that the embedded object is designed to be activated automatically. The document body contains a lure instructing the user to 'Enable editing', a common tactic to bypass security measures and trigger the exploit. The embedded artifact 'objdata_00_off00004def.bin' is the decoded OLE object data.

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_off00004def.bin
396a1acadc71791c060bc123bd655323c9402d20ef217216c44ed83e472db4a3
rtf-objdata-decoded RTF \objdata at offset 0x4DEF 1355 bytes