Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 b09b0158d45eace5…

MALICIOUS

RTF / .DOC

110.5 KB First seen: 2023-09-04
MD5: e544d5d19e8eab272d03c92c103dd9d5 SHA-1: 8c91848f8ee23dd892881359d4dc59c0cc99acfb SHA-256: b09b0158d45eace5c5e70ac8265b6300de0ab30e493dd9b29bb37f4cbf99920a
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution T1566.001 Phishing: Spearphishing Attachment T1059.005 Command and Scripting Interpreter: Visual Basic

The file is an RTF document that exploits the Equation Editor vulnerability, indicated by the RTF_EQUATION_EDITOR heuristic. It also contains OLE object data and an automatic link that forces OLE activation, suggesting the embedded object will be executed. The document body includes a lure to 'Enable editing' to bypass security measures, a common tactic for macro-based malware.

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_off000034bc.bin
5e6d2c1caaa29e5e8f45a526a8562fd27ee579933c65708ee1b0d09d9f66e16a
rtf-objdata-decoded RTF \objdata at offset 0x34BC 1626 bytes