Overview
overview
10Static
static
BS.exe
windows7_x64
10BS.exe
windows10_x64
10BuildS.exe
windows7_x64
10BuildS.exe
windows10_x64
10READS.exe
windows7_x64
10READS.exe
windows10_x64
10baseus_nowin.exe
windows7_x64
10baseus_nowin.exe
windows10_x64
10rbs.exe
windows7_x64
10rbs.exe
windows10_x64
10scan.exe
windows7_x64
1scan.exe
windows10_x64
1Analysis
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max time kernel
161s -
max time network
143s -
platform
windows10_x64 -
resource
win10-en-20211014 -
submitted
20-10-2021 09:41
Static task
static1
Behavioral task
behavioral1
Sample
BS.exe
Resource
win7-en-20210920
Behavioral task
behavioral2
Sample
BS.exe
Resource
win10-en-20211014
Behavioral task
behavioral3
Sample
BuildS.exe
Resource
win7-en-20210920
Behavioral task
behavioral4
Sample
BuildS.exe
Resource
win10-en-20211014
Behavioral task
behavioral5
Sample
READS.exe
Resource
win7-en-20210920
Behavioral task
behavioral6
Sample
READS.exe
Resource
win10-en-20211014
Behavioral task
behavioral7
Sample
baseus_nowin.exe
Resource
win7-en-20210920
Behavioral task
behavioral8
Sample
baseus_nowin.exe
Resource
win10-en-20210920
Behavioral task
behavioral9
Sample
rbs.exe
Resource
win7-en-20211014
Behavioral task
behavioral10
Sample
rbs.exe
Resource
win10-en-20210920
Behavioral task
behavioral11
Sample
scan.exe
Resource
win7-en-20211014
Behavioral task
behavioral12
Sample
scan.exe
Resource
win10-en-20210920
General
-
Target
BuildS.exe
-
Size
53KB
-
MD5
d0feecd8202129bb9c19823a04cd93ce
-
SHA1
631b2e3c26dfa53778d881e592cc9e499e7f98bb
-
SHA256
0dc4a2e2f49b2a6265a3c011d186a6f79ca8356d49d1c687465a5d994b6db38a
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SHA512
03676f15ee822f550e2dc5e979d205ce0f154d2e1062a7d8257931ca945c6f536de913f28f4abc0a399a0b1bacd380cbff3f26d0ec597c0d7593f349b121e097
Malware Config
Extracted
C:\how_to_back_files.html
Signatures
-
Modifies extensions of user files 11 IoCs
Ransomware generally changes the extension on encrypted files.
description ioc Process File renamed C:\Users\Admin\Pictures\ApproveStart.tiff => C:\Users\Admin\Pictures\ApproveStart.tiff.LOCK BuildS.exe File renamed C:\Users\Admin\Pictures\ReceiveConvertFrom.png => C:\Users\Admin\Pictures\ReceiveConvertFrom.png.LOCK BuildS.exe File renamed C:\Users\Admin\Pictures\RemoveTest.raw => C:\Users\Admin\Pictures\RemoveTest.raw.LOCK BuildS.exe File renamed C:\Users\Admin\Pictures\UnlockUninstall.png => C:\Users\Admin\Pictures\UnlockUninstall.png.LOCK BuildS.exe File opened for modification C:\Users\Admin\Pictures\ApproveStart.tiff BuildS.exe File opened for modification C:\Users\Admin\Pictures\CompressRestore.tiff BuildS.exe File renamed C:\Users\Admin\Pictures\CompressRestore.tiff => C:\Users\Admin\Pictures\CompressRestore.tiff.LOCK BuildS.exe File renamed C:\Users\Admin\Pictures\DisableMove.raw => C:\Users\Admin\Pictures\DisableMove.raw.LOCK BuildS.exe File renamed C:\Users\Admin\Pictures\SearchOpen.crw => C:\Users\Admin\Pictures\SearchOpen.crw.LOCK BuildS.exe File renamed C:\Users\Admin\Pictures\ShowClose.raw => C:\Users\Admin\Pictures\ShowClose.raw.LOCK BuildS.exe File renamed C:\Users\Admin\Pictures\ShowTrace.png => C:\Users\Admin\Pictures\ShowTrace.png.LOCK BuildS.exe -
Reads user/profile data of web browsers 2 TTPs
Infostealers often target stored browser data, which can include saved credentials etc.
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Drops desktop.ini file(s) 26 IoCs
description ioc Process File opened for modification C:\Users\Public\Libraries\desktop.ini BuildS.exe File opened for modification C:\Users\Public\Documents\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Videos\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Saved Games\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Pictures\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Contacts\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Downloads\desktop.ini BuildS.exe File opened for modification C:\Program Files (x86)\desktop.ini BuildS.exe File opened for modification C:\Users\Public\Pictures\desktop.ini BuildS.exe File opened for modification C:\Users\Public\Desktop\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Searches\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Pictures\Saved Pictures\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Pictures\Camera Roll\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Music\desktop.ini BuildS.exe File opened for modification C:\Program Files\desktop.ini BuildS.exe File opened for modification C:\Users\Public\Music\desktop.ini BuildS.exe File opened for modification C:\Users\Public\Downloads\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\OneDrive\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Favorites\Links\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Desktop\desktop.ini BuildS.exe File opened for modification C:\Users\Public\desktop.ini BuildS.exe File opened for modification C:\Users\Public\Videos\desktop.ini BuildS.exe File opened for modification C:\Users\Public\AccountPictures\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Links\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Favorites\desktop.ini BuildS.exe File opened for modification C:\Users\Admin\Documents\desktop.ini BuildS.exe -
Drops file in Program Files directory 64 IoCs
description ioc Process File opened for modification C:\Program Files\Microsoft Office\root\vfs\ProgramFilesX86\Microsoft Office\Office16\DCF\NativeShim.dll BuildS.exe File created C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\uss-search\js\nls\fr-ma\how_to_back_files.html BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\images\file_types\themes\dark\selection-actions2x.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.WindowsAlarms_10.1702.333.0_x64__8wekyb3d8bbwe\Assets\AlarmsAppList.contrast-black_targetsize-20.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.MicrosoftSolitaireCollection_3.14.1181.0_x64__8wekyb3d8bbwe\Assets\ThemePreview\Effects\part.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.MicrosoftSolitaireCollection_3.14.1181.0_x64__8wekyb3d8bbwe\Assets\MainPage\silverIcon.png BuildS.exe File created C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\ob-preview\js\nls\eu-es\how_to_back_files.html BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.MicrosoftSolitaireCollection_3.14.1181.0_x64__8wekyb3d8bbwe\Assets\HowToPlay\Pyramid\Goal_3.jpg BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\images\themes\dark\s_sortedby_hover_18.svg BuildS.exe File opened for modification C:\Program Files\WindowsApps\microsoft.windowscommunicationsapps_17.7906.42257.0_x64__8wekyb3d8bbwe\msproof7imm.dll BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.NET.Native.Runtime.1.4_1.4.24201.0_x86__8wekyb3d8bbwe\AppxBlockMap.xml BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.MicrosoftSolitaireCollection_3.14.1181.0_x64__8wekyb3d8bbwe\SharpDXEngine\Rendering\Shaders\Builtin\HLSL\ConstantsPerObjectInstanced.fx BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\on-boarding\images\themeless\pdf-ownership-rdr-ja_jp_2x.gif BuildS.exe File opened for modification C:\Program Files\WindowsApps\microsoft.windowscommunicationsapps_17.7906.42257.0_x64__8wekyb3d8bbwe\Office.UI.Xaml.Oart.dll BuildS.exe File opened for modification C:\Program Files\WindowsApps\microsoft.windowscommunicationsapps_17.7906.42257.0_x64__8wekyb3d8bbwe\images\contrast-white\HxCalendarBadge.scale-100.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.Office.OneNote_17.7668.58071.0_x64__8wekyb3d8bbwe\images\3838_32x32x32.png BuildS.exe File opened for modification C:\Program Files\Microsoft Office\root\vfs\ProgramFilesX64\Microsoft Analysis Services\AS OLEDB\140\msmdlocal.dll BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\digsig\js\nls\sk-sk\ui-strings.js BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.WindowsStore_11701.1001.874.0_neutral_~_8wekyb3d8bbwe\AppxBlockMap.xml BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.WindowsCalculator_10.1702.312.0_x64__8wekyb3d8bbwe\Assets\CalculatorWideTile.scale-200.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.Office.OneNote_17.7668.58071.0_x64__8wekyb3d8bbwe\images\7656_24x24x32.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.WindowsMaps_5.1611.10393.0_x64__8wekyb3d8bbwe\Assets\SecondaryTiles\Directions\Place\RTL\SmallTile.scale-200.png BuildS.exe File created C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\add-account\js\nls\sl-si\how_to_back_files.html BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.MSPaint_1.1702.28017.0_x64__8wekyb3d8bbwe\Assets\Logos\Square71x71\PaintSmallTile.scale-150.png BuildS.exe File opened for modification C:\Program Files\VideoLAN\VLC\plugins\video_filter\liboldmovie_plugin.dll BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.BingWeather_4.18.56.0_x64__8wekyb3d8bbwe\Assets\AppTiles\WeatherImages\210x173\6.jpg BuildS.exe File created C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\tracked-send\js\viewer\nls\nb-no\how_to_back_files.html BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\task-handler\js\nls\en-gb\ui-strings.js BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.WindowsStore_11701.1001.87.0_x64__8wekyb3d8bbwe\Assets\AppTiles\StoreWideTile.scale-200.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.WindowsSoundRecorder_10.1702.301.0_x64__8wekyb3d8bbwe\Assets\VoiceRecorderAppList.contrast-black_targetsize-40.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.WindowsMaps_5.1611.10393.0_neutral_split.scale-100_8wekyb3d8bbwe\Assets\SecondaryTiles\Collections\contrast-black\MedTile.scale-100_contrast-black.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.ZuneVideo_10.16112.11601.0_x64__8wekyb3d8bbwe\Assets\contrast-black\AppList.targetsize-24_contrast-black.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.MSPaint_1.1702.28017.0_x64__8wekyb3d8bbwe\Microsoft.Xaml.Interactivity.winmd BuildS.exe File opened for modification C:\Program Files\WindowsApps\microsoft.windowscommunicationsapps_17.7906.42257.0_x64__8wekyb3d8bbwe\images\6416_40x40x32.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.MicrosoftSolitaireCollection_3.14.1181.0_x64__8wekyb3d8bbwe\Assets\Themes\Aquarium\aquarium_12h.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.MicrosoftSolitaireCollection_3.14.1181.0_x64__8wekyb3d8bbwe\Assets\Themes\Western\mask\13c.png BuildS.exe File opened for modification C:\Program Files\VideoLAN\VLC\plugins\demux\libps_plugin.dll BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\tracked-send\js\plugins\tracked-send\images\cstm_brand_preview.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\microsoft.windowscommunicationsapps_17.7906.42257.0_x64__8wekyb3d8bbwe\images\GenericMailSmallTile.scale-200.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.BingWeather_4.18.56.0_x64__8wekyb3d8bbwe\Assets\AppTiles\WeatherIcons\30x30\9.png BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\images\s_sortedby_up_18.svg BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.XboxApp_25.25.13009.0_x64__8wekyb3d8bbwe\Assets\GamesXboxHubAppList.targetsize-72_contrast-white.png BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\pages-app\js\nls\fr-fr\ui-strings.js BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.Office.OneNote_17.7668.58071.0_x64__8wekyb3d8bbwe\images\OneNoteSectionLargeTile.scale-125.png BuildS.exe File opened for modification C:\Program Files\Microsoft Office\root\Office16\OSF.DLL BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\task-handler\js\nls\sv-se\ui-strings.js BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\send-for-sign\images\s_agreement_filetype.svg BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.DesktopAppInstaller_1.0.10252.0_neutral_split.scale-100_8wekyb3d8bbwe\Assets\contrast-black\AppPackageSmallTile.scale-100_contrast-black.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\DeletedAllUserPackages\Microsoft.Windows.Photos_16.511.8780.0_neutral_split.scale-100_8wekyb3d8bbwe\Lumia.ViewerPlugin\Assets\IconOpenInRefocus.scale-100.png BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\uss-search\js\nls\es-es\ui-strings.js BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\send-for-sign\js\nls\hr-hr\ui-strings.js BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.SkypeApp_11.8.204.0_x64__kzf8qxf38zg5c\SkypeApp\Designs\Flags\large\sg_60x42.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\DeletedAllUserPackages\Microsoft.WindowsSoundRecorder_10.1702.301.0_neutral_split.scale-125_8wekyb3d8bbwe\Assets\VoiceRecorderSplashScreen.contrast-black_scale-125.png BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\sqlite.dll BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\images\selection-actions.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.SkypeApp_11.8.204.0_x64__kzf8qxf38zg5c\SkypeApp\Designs\Emoticons\small\rain.png BuildS.exe File opened for modification C:\Program Files\Microsoft Office\root\vfs\ProgramFilesX86\Microsoft Office\Office16\DCF\Microsoft.Office.Interop.Access.dll BuildS.exe File created C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\core\dev\nls\fr-ma\how_to_back_files.html BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\images\S_IlluDCFilesEmpty_180x180.svg BuildS.exe File opened for modification C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\WebResources\Resource0\static\js\plugins\send-for-sign\js\nls\en-il\ui-strings.js BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.MicrosoftSolitaireCollection_3.14.1181.0_x64__8wekyb3d8bbwe\Assets\Buttons\Deal\New-Deal-up.png BuildS.exe File opened for modification C:\Program Files\WindowsApps\Microsoft.BingWeather_4.18.56.0_x64__8wekyb3d8bbwe\Assets\AppTiles\Spacer\5px.png BuildS.exe File created C:\Program Files\VideoLAN\VLC\lua\http\css\ui-lightness\how_to_back_files.html BuildS.exe File opened for modification C:\Program Files\WindowsApps\DeletedAllUserPackages\Microsoft.ZuneMusic_10.16112.11621.0_neutral_resources.scale-200_8wekyb3d8bbwe\Assets\contrast-white\LargeLogo.scale-200_contrast-white.png BuildS.exe