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

Static analysis result for SHA-256 bcac1e33956458b6…

MALICIOUS

Office (OLE) / .XLS

229.0 KB Created: 2020-09-20 21:17:44
MD5: bf9774e5063791aba95abb5b808aea43 SHA-1: 2774db354121fd9080d86623e8e854af967b14cf SHA-256: bcac1e33956458b61bbc185ad3861e385f863ec9bb9232e67eea95282929ce30
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1059.005 Visual Basic

The critical heuristics OLE_XLM_AUTOOPEN and OLE_XLM_DANGEROUS_FN indicate the presence of an Excel 4.0 Auto_Open macro. The macro script reconstructs and executes a PowerShell command to download a file named 'pd.bat' from the URL 'https://cutt.ly/4jsSu5Q' into the environment's temporary directory and then execute it. This indicates a downloader functionality.

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
62ee9cc006ed8c05436afb07321398ac484c4645bb2f79cc4b55e6a9df64ca51
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 1484 bytes