Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 1bc3acdc5ac58e8c…

MALICIOUS

Office (OLE) / .XLS

40.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-05-13
MD5: d3ff480e44dd0ae8a68de8e6d47c6425 SHA-1: 92b21f23eaf09a9fb96e4c4c0bd6a6fcaf123d06 SHA-256: 1bc3acdc5ac58e8cd434b35397666072cb28e62e7969f157146bcaa648f4e33e
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious Link/Object: Malicious File T1059.001 Command and Scripting Interpreter: PowerShell T1105 Ingress Tool Transfer

The file contains Excel 4.0 macros, specifically an Auto_Open macro, which is a known technique for executing malicious code. The macros are designed to download and execute a second-stage payload from a list of provided URLs. The ClamAV detection and the presence of multiple suspicious URLs strongly indicate this is a downloader, likely associated with the Emotet family. The macro uses the RUN function, which is a dangerous API for executing arbitrary code.

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