Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 06f3e15ad205552a…

MALICIOUS

RTF / .DOC

13.7 KB First seen: 2023-02-16
MD5: 2553184019edf232e24e2941c14c293a SHA-1: 20eeb5bc33959f8c606d176c0b3f304fd6cfe718 SHA-256: 06f3e15ad205552afc6b51b29992eae57f14a15f813314e330b1885c8e04f321
200 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an RTF document that contains an embedded OLE object specifically identified as related to Equation Editor, triggering heuristics for CVE-2017-11882. This indicates the document is designed to exploit this known vulnerability for initial code execution. The presence of ` tf1

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_off00001488.bin
22ffd82310b83d5f8f1686fc94e7b9eb8e0a981e3f30d3a2feed3b00bf72d8ac
rtf-objdata-decoded RTF \objdata at offset 0x1488 1872 bytes