BackDoor.DarkCrystal.231

Technical Information

To ensure autorun and distribution

Modifies the following registry keys

[HKCU\Software\Microsoft\Windows\CurrentVersion\Run] 'firefox' = '"C:\MSOCache\All Users\{90140000-0018-0409-1000-0000000FF1CE}-C\firefox.exe"'
[HKLM\Software\Microsoft\Windows\CurrentVersion\Run] 'firefox' = '"C:\MSOCache\All Users\{90140000-0018-0409-1000-0000000FF1CE}-C\firefox.exe"'
[HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon] 'Shell' = 'explorer.exe, "C:\MSOCache\All Users\{90140000-0018-0409-1000-0000000FF1CE}-C\firefox.exe"'
[HKCU\Software\Microsoft\Windows\CurrentVersion\Run] '<File name>' = '"%HOMEPATH%\Desktop\<File name>.exe"'
[HKLM\Software\Microsoft\Windows\CurrentVersion\Run] '<File name>' = '"%HOMEPATH%\Desktop\<File name>.exe"'
[HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon] 'Shell' = 'explorer.exe, "C:\MSOCache\All Users\{90140000-0018-0409-1000-0000000FF1CE}-C\firefox.exe", "%HOMEPATH%\Desktop\<File nam...
[HKCU\Software\Microsoft\Windows\CurrentVersion\Run] 'taskhost' = '"%WINDIR%\SchCache\taskhost.exe"'
[HKLM\Software\Microsoft\Windows\CurrentVersion\Run] 'taskhost' = '"%WINDIR%\SchCache\taskhost.exe"'
[HKCU\Software\Microsoft\Windows\CurrentVersion\Run] 'winlogon' = '"%ProgramFiles(x86)%\Windows Defender\winlogon.exe"'
[HKLM\Software\Microsoft\Windows\CurrentVersion\Run] 'winlogon' = '"%ProgramFiles(x86)%\Windows Defender\winlogon.exe"'
[HKCU\Software\Microsoft\Windows\CurrentVersion\Run] 'audiodg' = '"C:\MSOCache\All Users\{90140000-00A1-0409-1000-0000000FF1CE}-C\audiodg.exe"'
[HKLM\Software\Microsoft\Windows\CurrentVersion\Run] 'audiodg' = '"C:\MSOCache\All Users\{90140000-00A1-0409-1000-0000000FF1CE}-C\audiodg.exe"'

Creates or modifies the following files

<SYSTEM32>\tasks\firefoxf
<SYSTEM32>\tasks\firefox
<SYSTEM32>\tasks\<File name>t
<SYSTEM32>\tasks\<File name>
<SYSTEM32>\tasks\taskhostt
<SYSTEM32>\tasks\taskhost
<SYSTEM32>\tasks\winlogonw
<SYSTEM32>\tasks\audiodga
<SYSTEM32>\tasks\audiodg
<SYSTEM32>\tasks\winlogon

Modifies file system

Creates the following files

C:\msocache\all users\{90140000-0018-0409-1000-0000000ff1ce}-c\firefox.exe
%HOMEPATH%\desktop\xlacbejw.log
%HOMEPATH%\desktop\docwhqig.log
%HOMEPATH%\desktop\lhmrnddr.log
%HOMEPATH%\desktop\bjigalnn.log
%HOMEPATH%\desktop\ppjajvxn.log
%HOMEPATH%\desktop\ffgvsxnn.log
%HOMEPATH%\desktop\akfdlsxu.log
%HOMEPATH%\desktop\vucvigap.log
%HOMEPATH%\desktop\zuvjhcmx.log
%HOMEPATH%\desktop\xzzneemb.log
%HOMEPATH%\desktop\nawcqmwx.log
%HOMEPATH%\desktop\bwycwqlb.log
%HOMEPATH%\desktop\ftfgvyqs.log
%HOMEPATH%\desktop\edvlrjfw.log
%HOMEPATH%\desktop\nnghuhyk.log
%HOMEPATH%\desktop\kjioyjmx.log
%HOMEPATH%\desktop\yblxetts.log
%ProgramFiles(x86)%\windows defender\cc11b995f2a76d
C:\msocache\all users\{90140000-0018-0409-1000-0000000ff1ce}-c\0fc223bdacedc3
%HOMEPATH%\desktop\<File name>.exe
%HOMEPATH%\desktop\3613b562688f0d
%WINDIR%\schcache\taskhost.exe
%WINDIR%\schcache\b75386f1303e64
%ProgramFiles(x86)%\windows defender\winlogon.exe
C:\msocache\all users\{90140000-00a1-0409-1000-0000000ff1ce}-c\audiodg.exe
nul
C:\msocache\all users\{90140000-00a1-0409-1000-0000000ff1ce}-c\42af1c969fbb7b
%TEMP%\1kw0tdin.0.cs
%TEMP%\1kw0tdin.cmdline
%TEMP%\1kw0tdin.out
%TEMP%\jpmtpycafi
%TEMP%\gvxl9baywr.bat
%HOMEPATH%\desktop\hhivdmai.log
%HOMEPATH%\desktop\csqukvud.log

Deletes the following files

%TEMP%\1kw0tdin.0.cs
%TEMP%\1kw0tdin.out
%TEMP%\1kw0tdin.cmdline
%TEMP%\jpmtpycafi

Moves the following files

from %ProgramFiles%\microsoft office\office14\bcssync.exe to %ProgramFiles%\microsoft office\office14\bcssync.exe.exe

Network activity

Connects to

'17#.#24.220.79':80

TCP

HTTP POST requests

http://17#.#24.220.79/Async/ExternaljavascriptsecurepacketCpuGameprotectDefaultdbPublic.php

UDP

'localhost':123

Miscellaneous

Creates and executes the following

'%WINDIR%\schcache\taskhost.exe'
'<SYSTEM32>\cmd.exe' /C "%TEMP%\gvXL9BayWr.bat"' (with hidden window)
'%WINDIR%\microsoft.net\framework64\v4.0.30319\csc.exe' /noconfig /fullpaths @"%TEMP%\1kw0tdin.cmdline"' (with hidden window)

Executes the following

'<SYSTEM32>\schtasks.exe' /create /tn "firefoxf" /sc MINUTE /mo 9 /tr "'C:\MSOCache\All Users\{90140000-0018-0409-1000-0000000FF1CE}-C\firefox.exe'" /f
'<SYSTEM32>\cmd.exe' /C "%TEMP%\gvXL9BayWr.bat"
'<SYSTEM32>\schtasks.exe' /create /tn "audiodga" /sc MINUTE /mo 11 /tr "'C:\MSOCache\All Users\{90140000-00A1-0409-1000-0000000FF1CE}-C\audiodg.exe'" /rl HIGHEST /f
'<SYSTEM32>\schtasks.exe' /create /tn "audiodg" /sc ONLOGON /tr "'C:\MSOCache\All Users\{90140000-00A1-0409-1000-0000000FF1CE}-C\audiodg.exe'" /rl HIGHEST /f
'<SYSTEM32>\schtasks.exe' /create /tn "audiodga" /sc MINUTE /mo 12 /tr "'C:\MSOCache\All Users\{90140000-00A1-0409-1000-0000000FF1CE}-C\audiodg.exe'" /f
'<SYSTEM32>\schtasks.exe' /create /tn "winlogonw" /sc MINUTE /mo 9 /tr "'%ProgramFiles(x86)%\Windows Defender\winlogon.exe'" /rl HIGHEST /f
'<SYSTEM32>\schtasks.exe' /create /tn "winlogon" /sc ONLOGON /tr "'%ProgramFiles(x86)%\Windows Defender\winlogon.exe'" /rl HIGHEST /f
'<SYSTEM32>\schtasks.exe' /create /tn "winlogonw" /sc MINUTE /mo 9 /tr "'%ProgramFiles(x86)%\Windows Defender\winlogon.exe'" /f
'<SYSTEM32>\chcp.com' 65001
'<SYSTEM32>\schtasks.exe' /create /tn "taskhostt" /sc MINUTE /mo 13 /tr "'%WINDIR%\SchCache\taskhost.exe'" /rl HIGHEST /f
'<SYSTEM32>\schtasks.exe' /create /tn "taskhostt" /sc MINUTE /mo 11 /tr "'%WINDIR%\SchCache\taskhost.exe'" /f
'<SYSTEM32>\schtasks.exe' /create /tn "<File name>t" /sc MINUTE /mo 8 /tr "'%HOMEPATH%\Desktop\<File name>.exe'" /rl HIGHEST /f
'<SYSTEM32>\schtasks.exe' /create /tn "<File name>" /sc ONLOGON /tr "'%HOMEPATH%\Desktop\<File name>.exe'" /rl HIGHEST /f
'<SYSTEM32>\schtasks.exe' /create /tn "<File name>t" /sc MINUTE /mo 12 /tr "'%HOMEPATH%\Desktop\<File name>.exe'" /f
'%WINDIR%\microsoft.net\framework64\v4.0.30319\csc.exe' /noconfig /fullpaths @"%TEMP%\1kw0tdin.cmdline"
'<SYSTEM32>\schtasks.exe' /create /tn "firefoxf" /sc MINUTE /mo 5 /tr "'C:\MSOCache\All Users\{90140000-0018-0409-1000-0000000FF1CE}-C\firefox.exe'" /rl HIGHEST /f
'<SYSTEM32>\schtasks.exe' /create /tn "firefox" /sc ONLOGON /tr "'C:\MSOCache\All Users\{90140000-0018-0409-1000-0000000FF1CE}-C\firefox.exe'" /rl HIGHEST /f
'<SYSTEM32>\schtasks.exe' /create /tn "taskhost" /sc ONLOGON /tr "'%WINDIR%\SchCache\taskhost.exe'" /rl HIGHEST /f
'<SYSTEM32>\w32tm.exe' /stripchart /computer:localhost /period:5 /dataonly /samples:2