Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 24f5dbabd3500373…

MALICIOUS

Office (OLE) / .XLSX

104.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: ef9ffdaa18fe83103305387b7866f09d SHA-1: 18abf925cc0721cf17b50fdf23b6f18fe28d0489 SHA-256: 24f5dbabd3500373cd5465c7a73cd704b420887a6f8eb9bddcf3d3abb29dc607
262 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File

The sample contains Excel 4.0 macros with an Auto_Open entry, which is a critical finding. The macros reconstruct and execute URLs, indicating a downloader functionality. Specifically, the macro code reconstructs the string "h"&"t"&"t"&"p://c"&"ab"&"le"&"eq"&"uip"&"me"&"nt"&"man"&"ag"&"em"&"en"&"tr"&"et"&"ur"&"ns.c"&"o"&"m/w"&"p-a"&"dm"&"i"&"n/JPi"&"vi"&"zx"&"mi"&"wo"&"9A"&"5Ow"&"ys/" and other similar URLs, which are likely used to download and execute a second-stage payload. ClamAV detection further supports the Emotet family attribution.

Heuristics 6

  • 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 (5 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: Doc.Downloader.EmotetExcel02220-9938626-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.EmotetExcel02220-9938626-0
  • 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.
  • 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://cableequipmentmanagementreturns.com/wp-admin/JPivizxmiwo9A5Owys/
    • http://novawedevent.com/tmp/PA0rBwFszIpy/
    • https://www.altasolutions.asia/myfiles/myB984EnOlSJJ4b9/
    • https://www.sanskriticreations.net/wp-admin/iGdDEvnMusgGlIoaR/
    • http://kiwibeautyhouse.com/wp-includes/js/tinymce/themes/qzutpR1kPAPp54/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
be1ac9f30af65ef180310243cbba4a51ea41ae015d1d5e2b649c82e30f6f4b5c		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6365 bytes

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