Malicious RTF — malware analysis report

Static analysis result for SHA-256 8ebe63ddab0473c4…

MALICIOUS

RTF

261.2 KB Created: 2018-07-03 09:28:00 First seen: 2019-05-16
MD5: 069870411efd80822a87344b7e52009a SHA-1: 8696cb6279513ca40f8df2a4f0a487b61b7e67f4 SHA-256: 8ebe63ddab0473c45ff2630cde3303bfb256038599f328e53adf6ad7bdaf5207
262 Risk Score

Malware Insights

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

The file is an RTF document that exploits two critical vulnerabilities: CVE-2017-11882 (Equation Editor FONT record overflow) and CVE-2017-8759 (MSXML SAX OLE activation). These exploits are designed to execute arbitrary code, likely downloading and running a second-stage payload from the unknown URL found within the document. The presence of OLE object data further supports the exploitation of embedded objects for malicious purposes.

Heuristics 7

  • CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882
    Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
  • CVE-2017-8759 — MSXML SAX OLE activation critical CVE likely CVE_2017_8759
    RTF contains a hex-encoded OLE1 object for Msxml2.SAXXMLReader.6.0 followed by an embedded OLE compound document, and the document requests OLE activation. This matches the RTF staging shape used for CVE-2017-8759 SOAP/WSDL parser code injection.
  • ClamAV: Doc.Exploit.Cve_2017_11882-7570663-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Exploit.Cve_2017_11882-7570663-1
  • \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 OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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://schrott-stuttgart.com/.well-known/pki-validation//l/css/baba.msi In RTF body
    • http://schemas.microsoft.com/office/word/2003/wordmlIn RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000bf6b.bin rtf-objdata-decoded RTF \objdata at offset 0xBF6B 15672 bytes
SHA-256: af151fae213a9953e40bd2413aeb3f9b480d31fabd0cff008093d818a8fea7a6