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

Static analysis result for SHA-256 f6dae6a609999c86…

MALICIOUS

Office (OLE) / .XLSX

71.5 KB Created: 2020-05-20 08:20:55 Authoring application: Microsoft Excel
MD5: 9ca4284cb51bdae8b8fe2842331b2e9b SHA-1: b09dc553d0b55d34c1541aa54230ea076a0c79d7 SHA-256: f6dae6a609999c86dda0fe5f39dd4a30177bfc4a22b9fa662fb9626edf6badac
200 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious Link: Malicious File

The file contains Excel 4.0 macros, specifically an Auto_Open function, which is a known technique for executing malicious code. The macro is designed to download and execute a second-stage payload from the URL 'http://os.meduarncbx.com/CGVqBLj'. This indicates a dropper functionality, aiming to infect the user's system with further malware.

Heuristics 4

  • 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: Xls.Dropper.Agent-7866655-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Agent-7866655-0
  • 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
5c9b65ea9f599398f74aada51c5478866cf4094524afe2f8ef38ac6b53ecd45c		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 39481 bytes

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