Malicious RTF — malware analysis report

Static analysis result for SHA-256 aa76a4b87156dfc6…

MALICIOUS

RTF

3.3 KB First seen: 2023-01-10
MD5: 4b41078796a25956bdf3237fa5041e21 SHA-1: 57ab7ef8ff59472f9aa7d1b0a9d64ae5384bf476 SHA-256: aa76a4b87156dfc617f7a9cf57d080babedf6c501eb257de9dd29250ec4fb8f8
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The RTF document contains an embedded OLE object that triggers CVE-2017-11882. This vulnerability allows for arbitrary code execution when the object is activated, likely leading to the download and execution of a secondary payload. The presence of the 'equaTiOn.3' ProgID strongly indicates the use of the Equation Editor vulnerability.

Heuristics 5

  • Obfuscated Equation Editor ProgID + activation critical CVE related RTF_EQUATION_EDITOR
    RTF decodes to an Equation.3 ProgID from top-level \objdata hex after nested RTF junk groups are ignored, and the document also contains \objemb plus \objupdate activation. This is an obfuscated Equation Editor exploit surface associated with CVE-2017-11882 / CVE-2018-0802 families, but no exact malformed MTEF CVE primitive was recovered from this object.
  • 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.
  • \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_off00000079.bin
90daccc810a0be3dc6242b4509d9098c04cad2aedab07ed6d4fb170a4d7496eb		 rtf-objdata-decoded RTF \objdata at offset 0x79 1569 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.