Backdoor.Win32.Caphaw_QKKBAL_50b1125b50

Dynamic Analysis

Payload

No specific payload has been found.

Process activity

The Backdoor creates the following process(es):

50b1125b507e181a39c9c461b88a9e64.exe:372
Reader_sl.exe:1064
wuauclt.exe:344
jusched.exe:1056

File activity

The process 50b1125b507e181a39c9c461b88a9e64.exe:372 makes changes in a file system.

The Backdoor creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\V3GZR7DW\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\NTUSER.DAT.LOG (4416 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Cab5.tmp (54 bytes)
%Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\MetaData\2BF68F4714092295550497DD56F57004 (408 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\CAWSS1G7\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\I18RKULV\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\Content\94308059B57B3142E455B38A6EB92015 (54 bytes)
%Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\MetaData\94308059B57B3142E455B38A6EB92015 (408 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Cab1.tmp (49 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Tar6.tmp (2712 bytes)
%Documents and Settings%\%current user%\NTUSER.DAT (4644 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Tar4.tmp (2712 bytes)
%Documents and Settings%\%current user%\Application Data\Sun\Java\Deployment\SystemCache\6.0\25\svchost.exe (2436 bytes)
%Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\Content\2BF68F4714092295550497DD56F57004 (18 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Cab3.tmp (49 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Tar2.tmp (2712 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\RRK3NF11\desktop.ini (67 bytes)

The Backdoor deletes the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\Tar2.tmp (0 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Cab5.tmp (0 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Cab1.tmp (0 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Tar6.tmp (0 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Tar4.tmp (0 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Cab3.tmp (0 bytes)

The process wuauclt.exe:344 makes changes in a file system.

The Backdoor creates and/or writes to the following file(s):

%WinDir%\SoftwareDistribution\DataStore\Logs\edb.chk (100 bytes)
%WinDir%\SoftwareDistribution\DataStore\Logs\edb.log (3576 bytes)
%WinDir%\SoftwareDistribution\DataStore\DataStore.edb (100 bytes)

The Backdoor deletes the following file(s):

%WinDir%\SoftwareDistribution\DataStore\Logs\tmp.edb (0 bytes)

The process jusched.exe:1056 makes changes in a file system.

The Backdoor creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\jusched.log (347 bytes)

Registry activity

The process 50b1125b507e181a39c9c461b88a9e64.exe:372 makes changes in a system registry.

The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "40 1D 8C 7E 98 E2 0D A2 F9 7B 0E CF C5 73 A0 84"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cookies" = "%Documents and Settings%\%current user%\Cookies"

[HKLM\System\CurrentControlSet\Hardware Profiles\0001\Software\Microsoft\windows\CurrentVersion\Internet Settings]
"ProxyEnable" = "0"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache2"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache1"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CacheLimit" = "65452"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"MigrateProxy" = "1"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CacheLimit" = "65452"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"History" = "%Documents and Settings%\%current user%\Local Settings\History"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Directory" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common AppData" = "%Documents and Settings%\All Users\Application Data"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4]
"CacheLimit" = "65452"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache4"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache3"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Paths" = "4"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections]
"SavedLegacySettings" = "3C 00 00 00 16 00 00 00 01 00 00 00 00 00 00 00"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CacheLimit" = "65452"

To automatically run itself each time Windows is booted, the Backdoor adds the following link to its file to the system registry autorun key:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"CS3//bfAwjijv wH" = "%Documents and Settings%\%current user%\Application Data\Sun\Java\Deployment\SystemCache\6.0\25\svchost.exe"

Proxy settings are disabled:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyEnable" = "0"

The Backdoor deletes the following value(s) in system registry:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"AutoConfigURL"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyServer"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyOverride"

The Backdoor disables automatic startup of the application by deleting the following autorun value:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"ie4uinit.exe"

The process Reader_sl.exe:1064 makes changes in a system registry.

The Backdoor creates and/or sets the following values in system registry:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd73-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd72-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd75-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

Network activity (URLs)

URL	IP
hxxp://a26.d.akamai.net/msdownload/update/v3/static/trustedr/en/authrootseq.txt
hxxp://a26.d.akamai.net/msdownload/update/v3/static/trustedr/en/authrootstl.cab
ivypsz2n6xbl0xm.www5.fey.su	198.52.243.229
rdnkun08.fey.su	198.52.243.229
030wmu1vfbmo.fey.su	190.98.213.128
kz152m0v04g8c5t1v.fey.su	140.113.215.240
ob2jrbvgjf9xs.fey.su	198.52.243.229
www.download.windowsupdate.com	198.47.108.43
yq7rjidjyoy1a4.afn.cc	198.52.243.229
90tpctygxjx.eewuiwiu.cc	Unresolvable
879ikhbworxl55.eewuiwiu.cc	Unresolvable
wfk63li0deh5t9.eewuiwiu.cc	Unresolvable
d98derew.www5.eewuiwiu.cc	Unresolvable

Rootkit activity

The Backdoor installs the following user-mode hooks in ntdll.dll:

NtQueryDirectoryFile

Propagation

Removals

Remove it with Ad-Aware

1. Click (here) to download and install Ad-Aware Free Antivirus.
2. Update the definition files.
3. Run a full scan of your computer.

Manual removal*

1. Scan a system with an anti-rootkit tool.
   
2. Terminate malicious process(es) (How to End a Process With the Task Manager):

   50b1125b507e181a39c9c461b88a9e64.exe:372
   wuauclt.exe:344
   

3. Delete the original Backdoor file.
   
4. Delete or disinfect the following files created/modified by the Backdoor:

   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\V3GZR7DW\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\NTUSER.DAT.LOG (4416 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Cab5.tmp (54 bytes)
   %Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\MetaData\2BF68F4714092295550497DD56F57004 (408 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\CAWSS1G7\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\I18RKULV\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\Content\94308059B57B3142E455B38A6EB92015 (54 bytes)
   %Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\MetaData\94308059B57B3142E455B38A6EB92015 (408 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Cab1.tmp (49 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Tar6.tmp (2712 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Tar4.tmp (2712 bytes)
   %Documents and Settings%\%current user%\Application Data\Sun\Java\Deployment\SystemCache\6.0\25\svchost.exe (2436 bytes)
   %Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\Content\2BF68F4714092295550497DD56F57004 (18 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Cab3.tmp (49 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Tar2.tmp (2712 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\RRK3NF11\desktop.ini (67 bytes)
   %WinDir%\SoftwareDistribution\DataStore\Logs\edb.chk (100 bytes)
   %WinDir%\SoftwareDistribution\DataStore\Logs\edb.log (3576 bytes)
   %WinDir%\SoftwareDistribution\DataStore\DataStore.edb (100 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\jusched.log (347 bytes)

5. Delete the following value(s) in the autorun key (How to Work with System Registry):

   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "CS3//bfAwjijv wH" = "%Documents and Settings%\%current user%\Application Data\Sun\Java\Deployment\SystemCache\6.0\25\svchost.exe"

6. Clean the Temporary Internet Files folder, which may contain infected files (How to clean Temporary Internet Files folder).
   
7. Reboot the computer.
   

*Manual removal may cause unexpected system behaviour and should be performed at your own risk.

Static Analysis

Network Activity

Map

Strings from Dumps