Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 7a1d9b74743b984e…

MALICIOUS

RTF / .DOC

39.6 KB First seen: 2023-05-09
MD5: 36de832d7ca2ba819e41f8dcd18330d0 SHA-1: bd58867b4b5ed242634ff469479d119981087d26 SHA-256: 7a1d9b74743b984e06990b35c0ffec7ffd2e20e9a0c484f31f0aed84103be299
140 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a specific Equation Editor ProgID, and an \objupdate directive that forces activation. The document body includes a lure instructing the user to 'Enable editing' to view the content. This combination strongly suggests an exploit targeting the Equation Editor vulnerability (CVE-2017-11882) 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_off00005a0d.bin
931cf4da9ca1fb27bb08328b79f60b5a9f993049efe6355de7320ec0fc2146be
rtf-objdata-decoded RTF \objdata at offset 0x5A0D 1597 bytes