Malicious Office (OLE) / .XLSX — malware analysis report

Static analysis result for SHA-256 6acb4f4ab5308db9…

MALICIOUS

Office (OLE) / .XLSX

332.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 227d4c5f3e82f9b358f6c0c161655f8d SHA-1: 51fbb09a070e6f9fe2b99271a746b4a740c75d3b SHA-256: 6acb4f4ab5308db9bddef68d80c3575a3d266815e8324c29a8c60a68af7e263e
242 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open macro, which is a critical finding. This macro utilizes dangerous functions like RUN to execute external commands or URLs. The embedded URL 'https://19racks.com.br/ds/151120.gif' is likely used to download and execute a second-stage payload, aligning with the 'Doc.Downloader' ClamAV detection.

Heuristics 6

  • 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.
  • ClamAV: Doc.Downloader.Docusign0521-9864805-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Docusign0521-9864805-0
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://19racks.com.br/ds/151120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
4d5531650e0faf8764ddd7b14e6947143c32308cbf699d36f8845764b3b4560a		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 5603 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.