Malicious RTF — malware analysis report

Static analysis result for SHA-256 81cfae743033e3f1…

MALICIOUS

RTF

9.5 KB First seen: 2023-02-24
MD5: 7dd203f43399a41d6724e93c59c26142 SHA-1: 548c730164223fba7cfba7d21d61643dfe4b84f3 SHA-256: 81cfae743033e3f1584136c555591f2737b1171da71b1e207525cd02bca02709
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF document contains an embedded OLE object that leverages the Equation Editor vulnerability (CVE-2017-11882). The heuristic firings indicate that \objdata and \objupdate are used to force OLE activation, which is a common technique for exploiting this vulnerability. The embedded OLE object, decoded from objdata, is the primary artifact, and its execution is expected to lead to further malicious activity, such as downloading and executing a second-stage payload.

Heuristics 3

  • 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.
  • \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_off00000699.bin
2d4adbc6a3e50b2d0d7feb71f56a3a5ecbb52e6fe5700204607f47e644fca840		 rtf-objdata-decoded RTF \objdata at offset 0x699 1709 bytes

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