Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 4627c2dc4ff8bf1b…

MALICIOUS

RTF / .DOC

32.3 KB First seen: 2023-05-31
MD5: 47e540db3d4a739e9618175229628524 SHA-1: 49ea959dd39a27797cbe87fad183222ba0ede8be SHA-256: 4627c2dc4ff8bf1b5cf50480d2bae9e05fd277887b8d36e44882b11e4a4c21fe
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File

The RTF document contains an embedded OLE object with an Equation Editor ProgID, triggered by an \objupdate directive. This strongly suggests an attempt to exploit a known vulnerability, likely CVE-2017-11882, to execute arbitrary code when the user enables editing. The document body contains a lure to enable editing, common in macro-based or exploit-laden documents.

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_off00004f0a.bin
0db8e266d4e9df15636a350c8aca3bb48532e196236c0149a1c703f645274395
rtf-objdata-decoded RTF \objdata at offset 0x4F0A 1672 bytes