Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 e172534f43aacfc5…

MALICIOUS

Office (OLE) / .XLS

40.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-05-12
MD5: 91a620c3f613e17500aa6894e074ff02 SHA-1: 131a2d652e74d451f6488ca5f61431a9d01abc37 SHA-256: e172534f43aacfc50c5a9db8dd667ce4fc4cee92e53a007a808ff604bbc5a77e
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious File Execution: User Execution: Malicious File

The file is an Excel 4.0 macro-enabled spreadsheet. Heuristics indicate the presence of an Auto_Open macro that uses dangerous functions, specifically the RUN function. The extracted URLs are likely used to download and execute a second-stage payload, consistent with Emotet's typical behavior. The ClamAV signature also confirms this classification.

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-adc2d23d2dc26dd0-9950240-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-adc2d23d2dc26dd0-9950240-0
  • 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
214b0200160a0a56c6b45537e99f08bf5e131e2710192ec67ed6ddfaa9428b75
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6825 bytes