Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 f0fd812a966138d6…

MALICIOUS

Office (OLE) / .XLS

232.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-03-25
MD5: 0e06e8830272985449446420f8752a04 SHA-1: 296b5f01e57c9d2f5cf72fc860bd2da63f3aa6c1 SHA-256: f0fd812a966138d6a733619ceb4285ce56eefb9174e7d0415c25c55b13a4fe8a
282 Risk Score

Malware Insights

Emotet · confidence 95%

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

The file contains Excel 4.0 macros with an Auto_Open entry, which is a known technique for executing malicious code. The macros reconstruct and attempt to download payloads from multiple URLs, including 'http://contrid.com/6vwkQmRU/'. ClamAV detection as 'Xls.Downloader.Emotet-b600c9ff3ec1c136-9950239-0' strongly suggests the Emotet family. The presence of both XLM and VBA macros indicates a sophisticated downloader.

Heuristics 7

  • 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.
  • URL reconstructed from XLM cell array (6 URLs) critical OLE_XLM_CELL_ARRAY_URL
    Excel 4.0 macro sheet stages its payload URL across the BIFF8 Shared String Table (one quoted-char SST entry concatenated with & at runtime) or across individual numeric cells (one ASCII charcode per cell). The reconstructed URL is invisible to literal-bytes URL extraction because it is never contiguous in the workbook stream. URLs were recovered by walking the BIFF8 record stream and decoding SST entries plus LABELSST/RK/NUMBER cells.
  • ClamAV: Xls.Downloader.Emotet-b600c9ff3ec1c136-9950239-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-b600c9ff3ec1c136-9950239-0
  • 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.
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://contrid.com/6vwkQmRU/
    • http://ctfilms.com/ks/2ygJuGV0/
    • http://cordclipsorganizer.com/cable-holder-2e/a/
    • http://dahiaka.com/DND/JuBlOiT8Ixj/
    • https://www.colfincas.com/tmp/FvyLs/
    • http://contentunion.net/newwebsite/UXkkk/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
9782ec94f612fa6014316c57f3aba31c20f5ca1075c2c12ef31787a22df00283
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 7009 bytes
macros.bas
aaa8e4140b1a48ed914365038bfd1f4385374eef9f5c42b5b515efeb43137002
vba-macro oletools.olevba.extract_macros (decoded VBA source) 1781 bytes