Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 9b64a585f67fd878…

MALICIOUS

RTF / .DOC

35.9 KB First seen: 2023-04-14
MD5: 6e4f3b61856f4543c889c8f3e5b8f286 SHA-1: 3a2a6855f7b3f91818469a33161e9fea2c093621 SHA-256: 9b64a585f67fd87827727bb0eed3dd46763f90cb0cf1bec4735e4cc1bb22a7d5
180 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 RTF document contains an embedded OLE object, specifically targeting the Equation Editor, and uses an 'Enable editing' lure to trick the user into activating it. The presence of ".objupdate" further suggests an attempt to automatically activate the embedded object upon opening. This indicates a likely attempt to exploit vulnerabilities within the OLE object handler or execute embedded code.

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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off00004cdb.bin
a2de65e136d7f14cdb47821e2500b1327b05792c8faddeddda2f5419923f574d
rtf-objdata-decoded RTF \objdata at offset 0x4CDB 1977 bytes