Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 b73e7cd0825a3172…

MALICIOUS

RTF / .DOC

9.4 KB First seen: 2022-03-22
MD5: 14b630fa059a286a1f39baee8256230b SHA-1: 033daa06f04b53a618ea7c0233385e69c94a48c9 SHA-256: b73e7cd0825a31723cc6b15d5a44468b53ace7b28a3a2a445618d9ae64ae539f
121 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample is an RTF document that leverages the Equation Editor vulnerability (CVE-2017-11882), indicated by the RTF_EQUATION_EDITOR heuristic. The RTF_OBJUPDATE heuristic suggests that the embedded OLE object is automatically activated upon opening. This exploit chain is commonly used to download and execute a second-stage payload. No specific family could be identified.

Heuristics 3

  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000014c7.bin
da972dcffd5aff80c1705944d684ced5a23bb5189c15582aed96abf99174667b
rtf-objdata-decoded RTF \objdata at offset 0x14C7 1917 bytes