Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 ce868c3cd85acb99…

MALICIOUS

Office (OLE) / .XLS

217.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-11-08
MD5: e98525ed6bbd581d1af240f519c9d69e SHA-1: 590bf50a76eb3e327b37dd80f875461707eb0a61 SHA-256: ce868c3cd85acb99df28599fec809e3af99292f996755dbad8038118201bedd0
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Service Execution T1566.001 Phishing: Spearphishing Attachment

The file is an Excel 4.0 macro-enabled spreadsheet detected as malicious by ClamAV, specifically identified as Emotet. The presence of an Auto_Open macro and the use of dangerous formula APIs like RUN indicate an attempt to execute arbitrary code upon opening. This functionality is characteristic of Emotet's downloader capabilities, which typically fetch and execute further payloads.

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-b649c93692b4c9d9-9976616-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-b649c93692b4c9d9-9976616-0
  • 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
7ab8bae296ad9432cee5624e5f1ad744a80b8140ef71af99e7f6c57da9c919f6
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8277 bytes