Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 56e7d1b3dccc03d9…

MALICIOUS

Office (OLE) / .XLS

95.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-07-04
MD5: 3d2436e883a2c335ba5229170b2aee9d SHA-1: a3d888bd254730e5199b4dd25244dd02282f6773 SHA-256: 56e7d1b3dccc03d9f849dae44fa2ac32091265eeb72980a3b8321d04fa2b21fb
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Service Control T1566.001 Phishing: Spearphishing Attachment T1059.001 Command and Scripting Interpreter: PowerShell

The sample is an Excel 4.0 macro-enabled spreadsheet containing an Auto_Open function, a common technique for executing malicious code upon opening. ClamAV detection confirms it as Emotet, a known downloader family. The Auto_Open macro likely executes a dangerous formula to download and run a second-stage payload.

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-ea81817e7f807ab1-9952142-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-ea81817e7f807ab1-9952142-0
  • 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
af7e08eb74381f391d59ad043f1ef517fa450a796c57fe61d66c86ac41aaa1e8
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8147 bytes