Malicious RTF — malware analysis report

Static analysis result for SHA-256 2d03d1f52b4c84ae…

MALICIOUS

RTF

8.1 KB First seen: 2019-04-17
MD5: 76b81a304df6dd341e0401ca0d4850d6 SHA-1: 29192c5e0bfc0366bf73f259949c95517260e708 SHA-256: 2d03d1f52b4c84ae9912c3f5c3b95ebfb909098f363ac9696525ed6f6433f998
280 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object that exploits the CVE-2017-11882 vulnerability in Equation Editor. This vulnerability allows for arbitrary code execution when the object is activated. The file is classified as malicious due to this exploit.

Heuristics 6

  • 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
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off0000003f.bin rtf-objdata-decoded RTF \objdata at offset 0x3F 4135 bytes
SHA-256: f10cb9a7acea164f7a82efc50eaabfbbe3ee6c9f314d8f93aa2785c449e70c56