Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 9d4dde887284965c…

MALICIOUS

RTF / .DOC

12.3 KB First seen: 2022-03-15
MD5: 881bdb65541039b84660ea9110721e8b SHA-1: 006488987324324f2b89dd58c743d86a29f91ec6 SHA-256: 9d4dde887284965c3da6bcacaaf612544dc56fa72898d10d1028b006023bcf26
180 Risk Score

Malware Insights

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

The RTF file contains embedded OLE objects and specifically triggers the Equation Editor vulnerability (CVE-2017-11882). This indicates an attempt to execute arbitrary code by exploiting a known Microsoft Office vulnerability. The heuristics strongly suggest this exploit is present and active. No document body text was available for further contextual analysis.

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_off00001ff2.bin
e591885e7bca33b7edf18010d7e16fbd19f9b68b7169bd47a0b6246f2855f1b4
rtf-objdata-decoded RTF \objdata at offset 0x1FF2 2055 bytes