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

Static analysis result for SHA-256 b7b76e2efcecbb99…

MALICIOUS

Office (OLE) / .XLSX

132.0 KB Created: 2020-11-20 17:59:00 Authoring application: Microsoft Excel
MD5: 7ec88ed6a4c680e0014c93dc73f420ca SHA-1: a7560ca2e64aa263513b5be7d4a28209e629cc84 SHA-256: b7b76e2efcecbb99af4afe01a547fc80bc6bb40e29fdde6b1c980537ec5199d6
148 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File

The critical OLE_XLM_AUTOOPEN and OLE_XLM_DANGEROUS_FN heuristics indicate the presence of an Excel 4.0 macro designed to execute code. The macro reconstructs and executes a PowerShell command to download a file named 'gw.exe' from 'https://tinyurl.com/y73f3sez' and save it to the user's AppData directory. This indicates the file is a downloader for a second-stage payload.

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.
  • 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.
  • VBA project contains no executable statements low OLE_VBA_MACROS
    Document contains a VBA project, but extracted modules only contain attributes/options/comments and no executable statements.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
3b6924c61e5c7800e2fe9cc799b0223b1189d6e4b9df0de5a836e7b0a251bf82		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 1897 bytes
macros.bas
fed365d3401536fb63e11d0a36cc7c35338c0a8c74a96fb254c46366ad6287cd		 vba-macro oletools.olevba.extract_macros (decoded VBA source) 642 bytes

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