Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 3127282648cb5a0f…

MALICIOUS

RTF / .DOC

11.4 KB First seen: 2022-04-04
MD5: 60cf7073a59149355a00a32f063d1ca5 SHA-1: b51ea09f45f643f1c0b266a698d5833c897e7e7c SHA-256: 3127282648cb5a0fe3f1424ef55b7cb4350421079460c0a0219d6816ff04662b
121 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The sample is an RTF document containing OLE object data and specifically triggers heuristics related to the Equation Editor vulnerability (RTF_EQUATION_EDITOR) and OLE object activation (RTF_OBJUPDATE). This indicates a likely exploit attempt targeting CVE-2017-11882. The presence of these exploit-related heuristics strongly suggests the document is designed to execute malicious code upon opening, likely to download and run a secondary 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001d5b.bin
7421f8521507c61770f0d5315b91ccd323c4b486e35af0f45b93cff0ba3d17c6
rtf-objdata-decoded RTF \objdata at offset 0x1D5B 1900 bytes