Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 73c64360de74a79a…

MALICIOUS

RTF / .DOC

4.4 KB First seen: 2022-12-12
MD5: f276d086133436045b329c33a77e1a66 SHA-1: ed35a091c5c2b80fe7b1ea5c5174b5726068051f SHA-256: 73c64360de74a79a64bf671d38ea68b5fff43c449076e88dcade09fcfb815217
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF document contains an embedded OLE object that is specifically targeted by the CVE-2017-11882 vulnerability. The heuristics indicate that the Equation Editor is being activated, which is the mechanism used to exploit this known vulnerability. This exploit allows for arbitrary code execution, likely to download and run a secondary payload.

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_off00000072.bin
a02df7d12faacbe0407ba018baabcde54959d9a23405989fcc31896c2e161734		 rtf-objdata-decoded RTF \objdata at offset 0x72 2156 bytes

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