Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ccce7a3c30777622…

MALICIOUS

RTF / .DOC

26.1 KB
MD5: b2648c3c63442641d07309bae42ddb96 SHA-1: 52751f8a0b42e7acebbcd8ccc94c5d193b1d56af SHA-256: ccce7a3c307776221c5d21e5747c335bf49f20497d80c7e19f0ed9126920ee71
180 Risk Score

Malware Insights

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

The RTF file contains OLE object data and specifically triggers the CVE-2017-11882 vulnerability through the Equation Editor. This indicates an attempt to execute arbitrary code by exploiting a known Microsoft Office vulnerability. The decoded object's class is identified as EQUAtIoN.3, which is a strong indicator for this specific exploit.

Heuristics 5

  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001fbd.bin
67f1fb819f6f59d0e09e36b5782e881cbf79206d061a2ebfb2e7817a034a9d8c
rtf-objdata-decoded RTF \objdata at offset 0x1FBD 1793 bytes