Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 3744267b8221b370…

MALICIOUS

RTF / .DOC

27.9 KB
MD5: 8a3a84eb4aeb564a436d199f7e18ada2 SHA-1: 2e156dfb4b6795dd845b2f4e8529c8c5d53d49bc SHA-256: 3744267b8221b370ef4c3d1c75959e90f832a40473f3212de045c708fd11aff4
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.001 PowerShell T1204.002 Malicious File

The sample is an RTF document that contains embedded OLE object data and specifically triggers the Equation Editor exploit. The ".objupdate" directive forces the OLE object to activate, leading to the exploitation of the Equation Editor vulnerability. This technique is commonly used to download and execute a second-stage 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_off000020d1.bin
8c2e299d535db5d888cd36014ac1f3a49d920af05c0f71133d63ec4d4108600a
rtf-objdata-decoded RTF \objdata at offset 0x20D1 2003 bytes