Malicious RTF — malware analysis report

Static analysis result for SHA-256 6cae3b86f566781e…

MALICIOUS

RTF

261.1 KB Created: 2018-07-03 09:28:00 First seen: 2019-05-16
MD5: b197e4b4a7caeffd702245392148a805 SHA-1: 471a6b29fa940316441c05335d85c107dd7e482a SHA-256: 6cae3b86f566781e951888a9920f22a3dca813b0c0eb5c01b590ada702a54b0d
262 Risk Score

Malware Insights

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

The RTF file contains critical heuristic firings for CVE-2017-11882 and CVE-2017-8759, indicating exploitation of known vulnerabilities in Microsoft Equation Editor and MSXML SAX. The presence of embedded OLE objects and the ".objupdate" directive strongly suggest that these exploits are used to activate the embedded object, which likely downloads and executes a second-stage payload from the URL http://charlescuthbertson.com/main/cloud/fam.msi. The ClamAV detection further confirms the malicious nature of the file.

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://charlescuthbertson.com/main/cloud/fam.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: ad0463e6f0d557aca07d79ba585366d2424be814e3bfa67e3de935dcb61fd861

Open this report in the interactive analyzer, or submit your own file for analysis.