Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 94eaadd216e1f459…

MALICIOUS

RTF / .DOC

16.6 KB First seen: 2023-02-17
MD5: b5aaeb48aa761e373257a7caffbf37de SHA-1: 84731b4cfcc84346f37e0afcba5ba0aeb3ba7a0a SHA-256: 94eaadd216e1f459f8185b9f8cf7fdc61bf981e845cb1e6e9b982524ade8a1dd
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF document contains an embedded OLE object specifically identified as Equation Editor, triggering heuristics related to CVE-2017-11882. This indicates the file is designed to exploit this known vulnerability for initial code execution. The presence of ` 0 s24 tf1 ouicompat onrtf1 bidis charset0 Arial;` suggests potential for further exploitation or payload delivery.

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 1 \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_off00001fda.bin
f983aa9a9cfde2594b0c2130fc43325232dabf040d5955e24310cb3d27028623
rtf-objdata-decoded RTF \objdata at offset 0x1FDA 1885 bytes