Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 a239cb6d61bd98b5…

MALICIOUS

RTF / .DOC

16.7 KB
MD5: 3ac74ddc5fa4c646f8e9ec5a2f22242e SHA-1: 059debdb7afc25ac5a982866837bb31964dc1cac SHA-256: a239cb6d61bd98b5f6aa26b365db3e97b20f0736ce8d0eff2265fc8e0557d7f6
180 Risk Score

Malware Insights

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

The RTF file contains OLE object data and is specifically flagged for exploiting CVE-2017-11882 using the Equation Editor. This indicates a high likelihood of arbitrary code execution upon opening the document. No scripts were extracted, and the document body was unreadable, but the heuristics strongly point to a known exploit for initial access.

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_off00001406.bin
ab480dbcc44fa1f4e0d384c611eaf465c37c30de03d9853090f4479a70b53369
rtf-objdata-decoded RTF \objdata at offset 0x1406 1566 bytes