Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 addce3e25d10951b…

MALICIOUS

RTF / .DOC

31.0 KB First seen: 2023-05-19
MD5: b5962dc2702381a0dd0b1a313573d43d SHA-1: 6eb8416225d40f01c052c6c4e7a6444a57598a48 SHA-256: addce3e25d10951bed21ec5f58d1e5516ba9adaa62504e06fe981026159c0c64
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 sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The presence of the 'SE_ENABLE_LURE' heuristic indicates the document attempts to trick the user into enabling editing, which would activate the OLE object. This combination strongly suggests a malicious dropper designed to exploit CVE-2017-11882 to download and execute 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_off000041d5.bin
a85ae2259b66d52ff6a68cc8723c7948fc7e8ab92d3e44bb9c4968eb2597e453
rtf-objdata-decoded RTF \objdata at offset 0x41D5 1334 bytes