Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 9c4e33a0042463bd…

MALICIOUS

Office (OLE) / .XLS

55.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-06-22
MD5: 1ab330c73ae269f26052c0ebbc2b47da SHA-1: fe6cbd47900493711b71668c9cec4e32e4f3a62b SHA-256: 9c4e33a0042463bd2619155669acab567433fd4ca59c1d2789b28eb9b9adf4f8
200 Risk Score

Malware Insights

Emotet · confidence 95%

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

The sample is an Excel 4.0 macro-enabled spreadsheet. Heuristics indicate the presence of an Auto_Open macro that utilizes dangerous functions, specifically the RUN function. The macro constructs a URL, "http://inging/NgmBH48GCzovEIAgJ/Y/", which is likely used to download and execute a second-stage payload. ClamAV detection confirms this as Emotet.

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
849f3718ec0fd3673746b761d078b5d6767e9cb8cc0df7772d50cc7c5a2548d8
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8080 bytes