Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 7173cb9b94e6a369…

MALICIOUS

RTF / .DOC

22.0 KB First seen: 2022-11-10
MD5: 96df1656ef82e1fceeda0e2e1cc92bbb SHA-1: 015efeab1dda85663f7e63b705a71d942126e6f2 SHA-256: 7173cb9b94e6a36943b08df173aac5fb53a3f1c632ca3490d6f2cd99f92f6fc0
140 Risk Score

Malware Insights

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

The sample is an RTF document that contains an embedded OLE object with a specific Equation Editor ProgID, indicating an attempt to exploit a known vulnerability. The \objupdate directive further suggests that the embedded object is designed to be activated automatically. The heuristic SE_ENABLE_LURE also indicates that the document contains content designed to trick the user into enabling editing or macros, which is a common delivery mechanism for exploits.

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_off0000418f.bin
e9ade2d7060cd03515e033a94832e61ad499cc39f03eb1cf5937cbcfd537cf7e
rtf-objdata-decoded RTF \objdata at offset 0x418F 1630 bytes