Malicious RTF — malware analysis report

Static analysis result for SHA-256 8e95195cb1c71410…

MALICIOUS

RTF

8.2 KB First seen: 2019-08-04
MD5: 8e79e74169e111a03f614d0190db1e55 SHA-1: 89187d26404334c374609c3c41798b532c6796e3 SHA-256: 8e95195cb1c71410c3611911f0259fe264f7cab344f314f17e35ac1b298ee739
240 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 CVE-2017-11882 via Microsoft Equation Editor. This vulnerability allows for arbitrary code execution when the document is opened. The file is detected by ClamAV as Doc.Exploit.CVE_2017_11882-6934206-0, confirming its malicious nature. The primary attack vector is likely spearphishing.

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_off00000033.bin rtf-objdata-decoded RTF \objdata at offset 0x33 4149 bytes
SHA-256: 30bd1a4f14a0310e5e129c646aaec57271ea682fcd648cefa0eb2c796c906929