Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 52a4cd6bc0f1820e…

MALICIOUS

RTF / .DOC

26.7 KB First seen: 2022-11-22
MD5: 62d5cc0a508ebe7ffd6f819d8c848707 SHA-1: 578acc06941532ac44079473b07f2405de07857b SHA-256: 52a4cd6bc0f1820e4c408344108def990b48e3041716716e03daced2f5dbd1f8
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059.005 PowerShell T1204.002 User Execution: Malicious File

The RTF document contains an embedded OLE object with an Equation Editor ProgID, and an \objupdate directive that forces OLE activation. The document also contains a lure instructing the user to 'Enable editing', a common tactic to bypass macro security. This combination strongly suggests exploitation of the Equation Editor vulnerability to execute a malicious payload.

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_off00004db9.bin
48f379d417b2e7182494942a22cdd17a15fb793d4ad707fbcde77b8361cd7e1f
rtf-objdata-decoded RTF \objdata at offset 0x4DB9 1653 bytes