Malicious RTF — malware analysis report

Static analysis result for SHA-256 1bcb9621d80a0514…

MALICIOUS

RTF

13.0 KB First seen: 2020-08-25
MD5: d08f196c3c83ceaa354294ac26cf7040 SHA-1: 6c88811743b512df5399eba8d5f0a0f6dbeb1458 SHA-256: 1bcb9621d80a0514ebcff1c684b2327f57f4eda94bae348ab135193503eccc9a
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF document contains an embedded OLE object that triggers CVE-2017-11882 via Microsoft Equation Editor. This exploit allows for arbitrary code execution, likely to download and run a secondary payload. The specific ProgID 'EqUATIon.3' is a strong indicator of this exploit.

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_off00002467.bin rtf-objdata-decoded RTF \objdata at offset 0x2467 1716 bytes
SHA-256: 53f010205137e3583ceb010f4aeb78549334d140fd5f553bdfd0b022233cf024

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