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

Static analysis result for SHA-256 cf7659fd98225739…

MALICIOUS

Office (OLE) / .XLSX

115.5 KB Created: 2020-06-04 15:18:10 Authoring application: Microsoft Excel
MD5: dc3d3db84b39bcdbdce821cb95c336c2 SHA-1: 92723de864fed8f43eaecdfff04c92ff2709aadf SHA-256: cf7659fd9822573935a9083a716db6958d17605a462fbc5767d5bf357a2e915c
200 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1218.011 Signed Binary Proxy Execution: Rundll32 T1105 Ingress Tool Transfer T1059.003 Windows Command Shell

The sample is an Excel spreadsheet containing XLM macros, indicated by the OLE_XLM_AUTOOPEN and OLE_XLM_DANGEROUS_FN heuristics. The macros utilize ShellExecute and URLDownloadToFile APIs to download a payload from 'https://destgrena.at/3/tsk.dll'. The script also contains instructions for executing commands via regsvr32.exe and rundll32.exe, suggesting a multi-stage infection process.

Heuristics 6

  • Reference to URLDownloadToFile API critical SC_STR_URLDOWNLOAD
    Reference to URLDownloadToFile API
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • XLM Auto_Open with dangerous formula APIs high 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.
  • Visible LOLBin command execution instruction high SE_LOLBIN_RUN_COMMAND
    Document contains instructions or visible command text involving Windows script/execution tools such as PowerShell, mshta, cmd, rundll32, or regsvr32
  • 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://destgrena.at/3/tsk.dll

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
6ddf618535cce299f152f2770d03a9070644c2883abd77eae58f3fcb6e6eece2		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 35477 bytes

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