Malicious Office (OOXML) / .XLSM — malware analysis report

Static analysis result for SHA-256 734ea4eb932bdef9…

MALICIOUS

Office (OOXML) / .XLSM

166.6 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 14.0300
MD5: 55cee36dfdb444092e91fac52db27118 SHA-1: e415f4fc3c9b8ecd6f209a026b775baceb35940d SHA-256: 734ea4eb932bdef93443940b173fc6b9281c2420a6565fd9cbdd07461a3651ce
262 Risk Score

Malware Insights

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

This Excel 4.0 macro-enabled document (.XLSM) contains multiple critical heuristic firings indicating the presence of dangerous Excel 4.0 macro functions such as EXEC and CALL. These functions are used to construct a formula that calls external URLs, specifically 'https://yohsinsolutions.com/0QeH3HFbNyY/kk.html' and 'https://gtec24.com/0mqp0yN6/kk.html', likely to download and execute a second-stage payload. The ClamAV detection of 'Xls.Downloader.Qbot0421-9856653-0' further supports its malicious nature as a downloader.

Heuristics 6

  • Excel 4.0 macro sheet (4 sheet(s)) critical OOXML_XLM_MACROSHEET
    Spreadsheet contains an Excel 4.0 (XLM) macro sheet — XLM was a major Office malware vector during 2020-2022 and evaded many VBA-focused controls before Microsoft tightened XLM defaults. Even legitimate XLM use is rare in modern workbooks.
  • Excel 4.0 Auto_Open defined name critical OOXML_XLM_AUTOOPEN_DEFINEDNAME
    Workbook defines _xlnm.Auto_Open or _xlnm.Auto_Close while containing an XLM macro sheet. This is the OOXML/XLSB auto-execution shape for Excel 4.0 macros.
  • Dangerous XLM formula APIs: EXEC, FORMULA, CALL, HALT critical OOXML_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet uses formula APIs that call directly into Win32 (=CALL/=EXEC/=REGISTER/=FORMULA). These are the primitives used to download payloads, write files, and start processes from an XLM macro without invoking VBA.
  • ClamAV: Xls.Downloader.Qbot0421-9856653-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Qbot0421-9856653-0
  • Suspicious extracted artifact medium EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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 https://yohsinsolutions.com/0QeH3HFbNyY/kk.html
    • https://gtec24.com/0mqp0yN6/kk.html
    • http://ns.adobe.com/xap/1.0/
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/photoshop/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#
    • http://schemas.openxmlformats.org/spreadsheetml/2006/main
    • http://schemas.microsoft.com/office/excel/2006/main
    • http://schemas.openxmlformats.org/officeDocument/2006/relationships
    • http://schemas.openxmlformats.org/markup-compatibility/2006
    • http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml
3053dafa2d3f987ce513cbeee21a23bb155656d1a3bacf27e3c9fd23a98df2cd		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet3.xml 1245 bytes
xlm_sheet_01.xml
7c70a733295093fa9be986f7921d4989b1ff5b1c9e7d7c0416a4b8d6aa837808		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 204903 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 shell/COM execution token(s).
xlm_sheet_02.xml
6cb3ab47226c206f666f8830fc35f10e422712c9d53bd66c647d57a05f0b41bc		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet2.xml 4485 bytes
xlm_sheet_03.xml
95eb9ac669583f7114c029725ae2ac1b158fd43ff181b1370db5057cd2dc1558		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet4.xml 1082 bytes

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