Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 7dbe1a6305da4252…

MALICIOUS

RTF / .DOC

47.3 KB First seen: 2023-09-04
MD5: d213d39085c1cfefab62f8623d050872 SHA-1: 8fe409e5708209fd8832735aa8dcbf9524586092 SHA-256: 7dbe1a6305da4252f7f42d8fe13a264df7070516faef7806e0c219b69797dcde
140 Risk Score

Malware Insights

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

The file is an RTF document exploiting the Equation Editor vulnerability, indicated by the RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics. The SE_ENABLE_LURE heuristic confirms the document contains a lure to enable editing, which is a common tactic for macro-based malware droppers. The embedded OLE object data likely contains the exploit code and potentially a payload downloader.

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_off00003802.bin
acab534bda526b64f3aea184d2b2422b3ba3139fcfd377991ea92945b4a3d092
rtf-objdata-decoded RTF \objdata at offset 0x3802 1628 bytes