Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 f2cbd4a3f298e1c5…

MALICIOUS

Office (OLE) / .XLS

217.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-11-03
MD5: 3b3e49d4781c0878fdd883a25f6325ba SHA-1: 2a4d2494246e3c55a2f5ca31ec6caed4ccf10e2c SHA-256: f2cbd4a3f298e1c523ceaf39d263f62ecea5afd0f5306156bb146d86c2095367
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Service Execution T1059.001 PowerShell: PowerShell T1566.001 Phishing: Spearphishing Attachment

The file contains Excel 4.0 macros, specifically an Auto_Open function, which is a known technique for executing malicious code. ClamAV detection identifies it as 'Xls.Downloader.Emotet-b649c93692b4c9d9-9976616-0', strongly suggesting Emotet family involvement. The Auto_Open macro likely downloads and executes a secondary 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.
  • ClamAV: Xls.Downloader.Emotet-b649c93692b4c9d9-9976616-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-b649c93692b4c9d9-9976616-0
  • 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
3ab0c337700dce079a0ccadb959c81bfea6ee60c4aeeae37ba46cc81f4a280d0
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8304 bytes