Malicious RTF — malware analysis report

Static analysis result for SHA-256 b6315d291748fb23…

MALICIOUS

RTF

10.0 KB First seen: 2019-09-30
MD5: 5102777e86070b3c2aa1b1792439f952 SHA-1: 3d525b9d311691aa3df4e9a5a0d4c7461c5d6489 SHA-256: b6315d291748fb23d5bae56642371d0b48bbbb2599f10c8642cbd3be0e4eeda7
182 Risk Score

Malware Insights

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

The sample is an RTF document that contains embedded OLE object data and triggers the Equation Editor CLSID. This strongly indicates exploitation of CVE-2017-11882, a known vulnerability in Microsoft Equation Editor, which allows for arbitrary code execution. The document likely serves as a spearphishing attachment designed to exploit this vulnerability.

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: cd33fb49bd1784f68862552cb66f0293dc26b116d2d10ecdf6142f82860d5934