Malicious RTF — malware analysis report

Static analysis result for SHA-256 d506575da6731583…

MALICIOUS

RTF

204.2 KB First seen: 2019-05-31
MD5: 88f20e873f293cbe82f8e0fd944a36bc SHA-1: 1c933124f841049aba3efe9dbaa8b6cbdb2d1035 SHA-256: d506575da673158369f0fbac10744b7862358f6a38ec55a4bf8e046ce1341472
240 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object that exploits the CVE-2017-11882 vulnerability in Microsoft Equation Editor. This exploit is known to allow for arbitrary code execution, which is typically used to download and run a second-stage malicious payload. The ClamAV detection further confirms the malicious nature of the file.

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
  • 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.
  • ClamAV: Doc.Exploit.CVE_2017_11882-6934206-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Exploit.CVE_2017_11882-6934206-0
  • \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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001479.bin rtf-objdata-decoded RTF \objdata at offset 0x1479 44975 bytes
SHA-256: 04203ef7e8d87a42e73e8812f3ddc8be631d8347305628428f09a6a9a1fa72a9