Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 a7924978cc9446af…

MALICIOUS

Office (OLE) / .XLS

40.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-05-15
MD5: f26ee7b54c0fb63a5b354ae216c8caa6 SHA-1: 000ebdef433166934ff9ae59ca98909689b68bd3 SHA-256: a7924978cc9446af048e39a6632ede79f14d840f463784fbffee6f7d38d1fb07
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious Link: Malicious File T1059.001 Command and Scripting Interpreter: PowerShell

The file is an Excel 4.0 macro-enabled spreadsheet containing an Auto_Open macro, which is a known technique for executing malicious code upon opening. The macro uses dangerous formula APIs, specifically the RUN function, to download and execute a payload from a list of provided URLs. ClamAV detection confirms this as Emotet, a downloader family. The macro's intent is to download and execute a second-stage payload from 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-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
3c680580d6c572fd20a0c9546b3c387c5635a8ba1be4180a74910d19615b1490
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6911 bytes