Malicious RTF — malware analysis report

Static analysis result for SHA-256 8c40e8ce30bd7c25…

MALICIOUS

RTF

8.4 KB First seen: 2019-05-10
MD5: c2b01566d1c109bb80ee4a9ba84b522a SHA-1: d5423d207d7a7010fa3ee0827c4851db31a755a5 SHA-256: 8c40e8ce30bd7c25bd02e5db3a7b32ffa5baa029e88e038c21deb04caa767fb6
240 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object that exploits CVE-2017-11882 via Microsoft Equation Editor. This vulnerability allows for arbitrary code execution when the document is opened. The file is identified by ClamAV as Doc.Exploit.CVE_2017_11882-6934206-0, indicating a known exploit.

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_off00000032.bin rtf-objdata-decoded RTF \objdata at offset 0x32 4159 bytes
SHA-256: 705ccfcee2f9f546311f2eb0eda099940cd9ee8b1c477ff76e5fd8db3302a0e5