Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 128b6f2fe8e8b231…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:41:46 Authoring application: Microsoft Excel
MD5: 6524bda07471ccba89dfa520e55129e0 SHA-1: 2cbf8c653f4d5873de7bbfec5f6b68579d4d06fd SHA-256: 128b6f2fe8e8b231c1e09e1109a8102884f81345bce4c7ab53ad19c5d028c6ed
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample is an Excel file containing Excel 4.0 macros, indicated by the OLE_XLM_AUTOOPEN and OLE_XLM_DANGEROUS_FN heuristics. The presence of an Auto_Open defined name suggests that the macro will execute automatically upon opening the workbook. The dangerous formula APIs used in the macro indicate it is designed to perform malicious actions, such as downloading and executing a payload.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
328d6728f2ffe180c6bbd856525764753c1246de8e607165c9e1a7aa60bcfe1c		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6782 bytes

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