Malicious RTF — malware analysis report

Static analysis result for SHA-256 de52bc4a4b3fa352…

MALICIOUS

RTF

261.2 KB Created: 2018-07-03 09:28:00
MD5: 7aaf98dfa5080b17e9ce187bf52809cc SHA-1: 7d4a66610ca0d59fc501d97f8f1e545bf5a2e53e SHA-256: de52bc4a4b3fa352ac26d9c0b910949a57e51661219246a84cc78d8215318d65
262 Risk Score

Malware Insights

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

The sample is an RTF document that exploits known vulnerabilities in Microsoft Equation Editor (CVE-2017-11882) and MSXML SAX (CVE-2017-8759). These exploits are designed to execute arbitrary code, likely to download and run a secondary payload from the embedded URL. The ClamAV detection further confirms the malicious nature of the file, specifically identifying it as Doc.Exploit.Cve_2017_11882-7570663-1.

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 https://www.miracleworkstudios.com/wp-content/uploads/2019/12/app/yhccjr.msi
    • http://schemas.microsoft.com/office/word/2003/wordml

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000bf6b.bin
e43011cc9cc59fc7e5deff3e203fe5f69c686f6be2856bb302eb4e005142c223
rtf-objdata-decoded RTF \objdata at offset 0xBF6B 15672 bytes