Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 9746aa1e975bfec4…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:42:22 Authoring application: Microsoft Excel
MD5: 6409b4e1ed32e4e77c667f20436b4267 SHA-1: c68e5d02a82571aa138e1609fccb21d87adf8ca8 SHA-256: 9746aa1e975bfec44276bacdaa546c1a2ff1770e43104c5305efd8d41a5b1627
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled document detected with critical heuristics for Auto_Open functionality and the use of dangerous formula APIs. The presence of an Auto_Open entry indicates that the macro will execute automatically when the workbook is opened, which is a common technique for delivering malicious payloads. No specific URLs or hashes were extracted, but the technique strongly suggests a downloader or initial execution stage.

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
76e2953458178a56153ee74dd1cb9b6538998566987275d5020b503c1d5f2cd1
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6684 bytes