Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f6ff722eb25d04d2…

MALICIOUS

RTF / .DOC

26.0 KB First seen: 2022-11-23
MD5: 6b2016dc99a6adbb0f7354674e5db3f4 SHA-1: a5e510cd04b00a59e486520f629d7942211e3044 SHA-256: f6ff722eb25d04d2d6a8f024c4e570abb07b4450fd14fbd491230b9953c5032f
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit a known vulnerability. The SE_ENABLE_LURE heuristic confirms the document instructs the user to enable editing, a common tactic for malware droppers. The RTF_OBJUPDATE heuristic further suggests that the OLE object is configured to activate automatically upon enabling editing.

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_off00004c81.bin
41ac38eb6f531cad50a5952c6a238d818ef46fda95e8c36d4e3356f374b8ee61
rtf-objdata-decoded RTF \objdata at offset 0x4C81 1539 bytes