Malicious RTF — malware analysis report

Static analysis result for SHA-256 5cfe810282ca0072…

MALICIOUS

RTF

55.9 KB First seen: 2023-09-09
MD5: 9c104fa0210a291c44d1a4073577a214 SHA-1: 41666f04baa60a2ef27c066c68f4956ba8e30bbe SHA-256: 5cfe810282ca0072ea63459dd3f9933087785d397d5968eee9547628af7323fa
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 file is an RTF document containing an embedded OLE object, specifically targeting the Microsoft Equation Editor vulnerability. The document body contains a lure instructing the user to 'click Enable editing', which is a common tactic to bypass security measures and trigger the exploit. The embedded object and the specific heuristic firings strongly indicate an attempt to exploit this known vulnerability, likely leading to the execution of a secondary payload.

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_off000030ae.bin
6eb1feb0c9a4aedb1953feec8376b4a3b898e6ca42a8b2a11e0082b7aa298746
rtf-objdata-decoded RTF \objdata at offset 0x30AE 1836 bytes