Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 55c686d84dea4822…

MALICIOUS

RTF / .DOC

19.5 KB
MD5: 7bb6f0d6341af12b707f49f7d86cf6ff SHA-1: 4c67a51b467ba165d54baf5250ba7892b3ff1ad1 SHA-256: 55c686d84dea4822fe6549d2c138b4459be82a3f8c6bd8657c2df65f0a19544d
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.001 PowerShell

The sample is an RTF document that contains embedded OLE object data and triggers an objupdate event, indicating exploitation of the Equation Editor vulnerability (CVE-2017-11882). This technique is commonly used to achieve arbitrary code execution. The specific exploit mechanism is identified by the RTF_EQUATION_EDITOR heuristic. The embedded OLE object data likely contains shellcode or a payload designed to download and execute a second-stage malware.

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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001931.bin
22b461ecf569dfbe7dacabbcd4aef4a73d94a9479db8b6f60f56e3d4a02d80bf
rtf-objdata-decoded RTF \objdata at offset 0x1931 1889 bytes