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

Static analysis result for SHA-256 e1cf9de2c977ab56…

MALICIOUS

Office (OOXML) / .XLSM

166.6 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 14.0300
MD5: fd5f31c8f168fb398b824b5eed5cd5c4 SHA-1: 85d334ebb60ee150de3a59c60ea4ce662fb02c28 SHA-256: e1cf9de2c977ab56dd493060eba1e1b3581fa5b43115e66f626a6e12e9d4bf36
260 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious File: User Execution: Malicious File T1105 Ingress Tool Transfer

The file is an Excel macro-enabled sheet (XLSM) containing Excel 4.0 macros. Critical heuristics indicate the use of dangerous XLM formula APIs like EXEC and CALL, which are commonly used to download and execute payloads. The document body and extracted URLs point to two suspicious domains that likely host the second-stage payload. The ClamAV detection as '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