Malicious RTF — malware analysis report

Static analysis result for SHA-256 cd68e1a1844f2c0d…

MALICIOUS

RTF

14.2 KB First seen: 2023-02-27
MD5: 4968c857b8a702901d0206d7de15848f SHA-1: 0006f6d2eb8038649e0a09441a03725bbaaa2c57 SHA-256: cd68e1a1844f2c0dc4b5a3b8468ed36cfac0d5cb9fe980ebb660751f76f87afe
200 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566 Phishing T1204.002 Malicious File

The sample is an RTF document that leverages the Equation Editor vulnerability (CVE-2017-11882) through a specially crafted OLE object. This technique is commonly used to deliver a second-stage payload. The presence of RTF_OBJDATA, RTF_OBJAUTLINK, RTF_EQUATION_EDITOR, and RTF_OBJUPDATE heuristics strongly indicates exploitation of this known vulnerability.

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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001d60.bin
9521b2c829758cc7ef90540f435c80ca06825796fde4d04bbb2d3223c02dd429		 rtf-objdata-decoded RTF \objdata at offset 0x1D60 1517 bytes

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