Malicious RTF — malware analysis report

Static analysis result for SHA-256 e23e5e78b89b0fc2…

MALICIOUS

RTF

10.0 KB First seen: 2019-09-30
MD5: 83cf506c625a00ec6608332ee73e0f66 SHA-1: 3ec3166a1e987a912980a29e57bf03b01f079875 SHA-256: e23e5e78b89b0fc2cff2accc1c0e6bf6e83b27c0e569e2371e9142e565643cc1
182 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF file contains an embedded OLE object that leverages the Equation Editor vulnerability (CVE-2017-11882). This vulnerability allows for arbitrary code execution when the object is activated, typically through user interaction or an objupdate directive. The presence of the Equation Editor CLSID and the objupdate heuristic strongly indicate exploitation for client execution, likely delivered as a spearphishing attachment.

Heuristics 5

  • Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • ClamAV: Rtf.Exploit.CVE_2017_11882-6584355-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_11882-6584355-1
  • \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
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.microsoft.com/office/word/2003/wordml In RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000005e8.bin rtf-objdata-decoded RTF \objdata at offset 0x5E8 3627 bytes
SHA-256: 020a0fbc0cae4cda4e7199998c84e1955bedeb2523846961bb23c3c7e73873b1