Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 a0de1f3af78bef68…

MALICIOUS

Office (OLE) / .XLS

55.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-06-22
MD5: b4aa7a6790d8d0a4484fee5c9d3edd91 SHA-1: f2c45f31e6a70b35bd108795fdcb6691399ff1eb SHA-256: a0de1f3af78bef68ddfcabf4b7cedfa0e466ac65648a5e81e591702b463c96b1
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File

The file is an Excel 4.0 spreadsheet containing an Auto_Open macro, which is a known technique for executing malicious code. ClamAV identifies this as Emotet, a downloader family. The macro uses dangerous functions like RUN, indicating it likely downloads and executes a second-stage payload. The presence of the Auto_Open defined name and the use of dangerous formula APIs strongly suggest malicious intent.

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-aa87d5786a858772-9953435-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-aa87d5786a858772-9953435-0
  • 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
dd6897f0b46722ba0cb2a6b6edf5e163635377bf70368882494f2fd92495d40b
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 7832 bytes