Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 75332a1cbe932060…

MALICIOUS

RTF / .DOC

14.3 KB
MD5: 2e5ed849641983ec2fa93d678147e0f8 SHA-1: be88db585148a200ed580dcf928f3bfe03072fe9 SHA-256: 75332a1cbe932060b22974c64aa21bbd53f2e7dd6c92d4c7a24cf2f3afc4068a
120 Risk Score

Malware Insights

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

The sample is an RTF document containing embedded OLE object data and specifically triggers heuristics for the Equation Editor vulnerability. The \objupdate directive indicates an attempt to force the activation of this embedded object, which is a known method for exploiting Equation Editor to achieve code execution. The presence of these indicators strongly suggests the document is designed to exploit this vulnerability to download and execute a secondary payload.

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_off000009f0.bin
717364e550b925f2c7cb65bc755df4f703f2de19984057814521714a35ba73ea
rtf-objdata-decoded RTF \objdata at offset 0x9F0 1561 bytes