Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 3dcb45486593d95f…

MALICIOUS

RTF / .DOC

4.2 KB First seen: 2022-07-22
MD5: ca054f9a40ddc91ea81c3b979b060456 SHA-1: fe86a8a6430bc149fe8189046daaffc35dc7b2bf SHA-256: 3dcb45486593d95f7e0f3f4bd73c35f47f44e7efd26cbaa563d2de33e8583e77
120 Risk Score

Malware Insights

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

The RTF file contains embedded OLE object data and triggers an objupdate event, strongly indicating the exploitation of the Equation Editor vulnerability (CVE-2017-11882). This technique is commonly used to download and execute a secondary payload. The specific exploit mechanism is confirmed by the RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristic firings.

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_off0000007b.bin
c823f218fd7295df11584257418382be74a983b9c2cf047dcc94701a0d8284fe
rtf-objdata-decoded RTF \objdata at offset 0x7B 1747 bytes