Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 238eb78391817758…

MALICIOUS

RTF / .DOC

204.4 KB First seen: 2023-10-25
MD5: b27994feece8f6a90b27b4cc28999987 SHA-1: 27b5a76f48f506763d61721a1d7288a553687c90 SHA-256: 238eb783918177587a892395fafdb7dce36deb2b0a153855a5d6a75bddf8f752
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1566 Phishing T1566.001 Phishing: Spearphishing Attachment

The sample is an RTF document that contains an embedded OLE object, specifically identified as an Equation Editor exploit. The document body includes a lure instructing the user to 'enable editing' and implies a need to view financial statements, a common tactic to bypass security measures. The presence of ` tf_objdata` and ` tf_objemb` heuristics further confirms the embedding of malicious content, likely an executable payload.

Heuristics 5

  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000026ad.bin
5d7d2fb4c31ced58bf7097d162b2ec2bb742bf5a145d63d6ac1ed90780ac05dd
rtf-objdata-decoded RTF \objdata at offset 0x26AD 2215 bytes