Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 78dc778e3611cbd4…

MALICIOUS

Office (OLE) / .XLS

63.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-06-15
MD5: b6dcfdef8cdb5fb6ed8a587efab55940 SHA-1: 3e2dd48edcfa11c268c6a9889a00be1f2fd69909 SHA-256: 78dc778e3611cbd43d153934d873763d0e2a886033a15108b041964645039426
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and exhibits critical heuristic firings related to Excel 4.0 macros, specifically an Auto_Open entry that utilizes dangerous formula APIs. The macro code concatenates strings to form multiple URLs, indicating its purpose is to download and execute a secondary payload. The presence of the 'Emotet' family in the ClamAV detection name strongly suggests this attribution.

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
81a890043a2bf9bada66e5f829f683706b013cf3d1f82e11ea536e934629d60f		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8316 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.