Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 3b5ab13cf874330f…

MALICIOUS

RTF / .DOC

20.2 KB
MD5: 67a7d78b65184dc159e07953aed8155b SHA-1: 9fa8dcf44d549b2384a0f6e862ec7dd6be0cb2df SHA-256: 3b5ab13cf874330f81f453e37b6baf5a0ddab305e5913bdecbd111bdd7ac439d
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.001 PowerShell

The sample is an RTF document containing OLE object data and specifically triggers heuristics related to Equation Editor exploitation. The ".objdata" and ".objupdate" sections indicate that embedded OLE objects are present and will be activated. This strongly suggests an attempt to exploit a known vulnerability in the Equation Editor component to achieve code execution. The embedded "objdata_00_off0000196f.bin" artifact is the decoded OLE object data, which is the likely carrier of the exploit.

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_off0000196f.bin
b6d3d5bc33bd62cd58b9bf0dc9678db27aeb680435cc6c9b5a5d60e3e19e8b9c
rtf-objdata-decoded RTF \objdata at offset 0x196F 1854 bytes