Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 10972a3ba0d16962…

MALICIOUS

Office (OLE) / .XLS

60.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-06-15
MD5: a8ee8fe15cf9bb9a5aa873a97e18976e SHA-1: c810d6d1751fe1a5f5bfb30ec63158f3ed0d8e3c SHA-256: 10972a3ba0d16962e261565ac9db6e67f96ac7986bd62b26a6eab8a896c0a0f8
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample is an Excel file containing Excel 4.0 macros, specifically an Auto_Open function that utilizes dangerous API calls. ClamAV identifies this as Emotet, a known downloader. The macro is designed to execute and likely download a second-stage payload from one of the embedded URLs.

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.Downloader.Emotet-ea85817e7e81383e-9951566-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-ea85817e7e81383e-9951566-0
  • 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
d77c0e98c974009fe5584bce5e0ffd72a8b15ac4e83c1240090b3dfbcca2aa7b
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8320 bytes