Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 66c90da724522e2a…

MALICIOUS

RTF / .DOC

14.9 KB
MD5: 7c3096849800983fcca8950b478f3a51 SHA-1: bc6cbfe2e027c8545b666a50aab623e1dfb683c0 SHA-256: 66c90da724522e2ae88a5e0847fe56d79b730c5ecf77961503e1c27130343a41
240 Risk Score

Malware Insights

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

The sample is an RTF document that contains an embedded OLE object. Heuristics indicate a critical vulnerability in Equation Editor (CVE-2017-11882) is being exploited. This exploit typically leads to the execution of arbitrary code, which is then used to download and run a secondary payload. The document body is heavily obfuscated and does not provide clear textual lures.

Heuristics 5

  • 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.
  • Equation Editor CLSID critical 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001a45.bin
20eda1b81083c6e610b34de1f547a98511112c7d7f7cc0b5ad511640d4492001
rtf-objdata-decoded RTF \objdata at offset 0x1A45 4143 bytes