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PUA_DNSUnlocker

February 05, 2016
 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

796,877 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

05 Feb 2016

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan creates the following folders:

  • %User Temp%\is-B4THV.tmp
  • %User Temp%\is-GFV3R.tmp
  • %User Temp%\is-GFV3R.tmp\_isetup
  • %Program Files%\DNS Unlocker

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

Other System Modifications

This Trojan deletes the following files:

  • %Program Files%\DNS Unlocker\dnsparish.exe
  • %Program Files%\DNS Unlocker\ZonaTools.XPlorerBar.dll
  • %Program Files%\DNS Unlocker\Microsoft.Win32.TaskScheduler.dll
  • %Program Files%\DNS Unlocker\Info.rtf
  • %Windows%\Tasks\Temp{8702343a-e112-4b32-bde9-65d01e3bd548}.job

(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

It adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b

HKEY_LOCAL_MACHINE\Software\5da059a482fd494db3f252126fbc3d5b\
Settings

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
SystemCertificates\ROOT\Certificates\
26D9E607FFF0C58C7844B47FF8B6E079E5A2220E

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b
FX = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b
SDP1 = "00001"

HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b
SDP2 = "00001"

HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b
UID = "4215e9a92c8f40eeb87f47e25dd1ca6b"

HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b
DP = "51"

HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b\
Settings
InstallPath = "%Program Files%\DNS Unlocker"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
Inno Setup: Setup Version = "5.5.5 (a)"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
Inno Setup: App Path = "%Program Files%\DNS Unlocker"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
InstallLocation = "%Program Files%\DNS Unlocker"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
Inno Setup: Icon Group = "DNS Unlocker"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
Inno Setup: User = "Wilbert"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
Inno Setup: Language = "english"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
DisplayName = "DNS Unlocker version 1.4"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
UninstallString = "%Program Files%\DNS Unlocker\unins000.exe "

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
QuietUninstallString = "%Program Files%\DNS Unlocker\unins000.exe /SILENT"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
DisplayVersion = "1.4"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
Publisher = "www.dnsunlocker.com"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
NoModify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
NoRepair = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
InstallDate = "20160112"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
MajorVersion = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1
MinorVersion = "4"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
SystemCertificates\ROOT\Certificates\
26D9E607FFF0C58C7844B47FF8B6E079E5A2220E
Blob = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b
status = "1"

It deletes the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
{E1527582-8509-4011-B922-29E3FB548882}_is1

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\is-b4thv.tmp\{malware file name}.tmp
  • %User Temp%\is-GFV3R.tmp\_isetup\_shfoldr.dll
  • %User Temp%\is-GFV3R.tmp\ConsoleApplication1.dll
  • %User Temp%\is-GFV3R.tmp\config_tmp.ini
  • %Program Files%\DNS Unlocker\unins000.dat
  • %Program Files%\DNS Unlocker\is-IQEB6.tmp
  • %Program Files%\DNS Unlocker\is-BH9O5.tmp
  • %Program Files%\DNS Unlocker\is-40728.tmp
  • %Program Files%\DNS Unlocker\is-0B730.tmp
  • %Program Files%\DNS Unlocker\is-NQIE0.tmp
  • %Program Files%\DNS Unlocker\is-4GB98.tmp
  • %Program Files%\DNS Unlocker\is-0MG6L.tmp
  • %Program Files%\DNS Unlocker\is-FGS3U.tmp
  • %Program Files%\DNS Unlocker\is-4H09L.tmp
  • %Program Files%\DNS Unlocker\is-JQ86F.tmp
  • %Program Files%\DNS Unlocker\is-MRMNO.tmp
  • %Program Files%\DNS Unlocker\is-JCAKC.tmp
  • %Program Files%\DNS Unlocker\is-PSE2S.tmp
  • %Program Files%\DNS Unlocker\is-5577I.tmp
  • %Program Files%\DNS Unlocker\is-REKC9.tmp
  • %Program Files%\DNS Unlocker\is-H6B63.tmp
  • %Windows%\Tasks\DNSPARISH.job
  • %Program Files%\DNS Unlocker\settings.ini

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}.143.56

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.8

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • 5da059a482fd494db3f252126fbc3d5b
  • In HKEY_LOCAL_MACHINE\Software\5da059a482fd494db3f252126fbc3d5b
    • Settings
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall
    • {E1527582-8509-4011-B922-29E3FB548882}_is1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\ROOT\Certificates
    • 26D9E607FFF0C58C7844B47FF8B6E079E5A2220E

Step 3

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b
    • FX = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b
    • SDP1 = "00001"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b
    • SDP2 = "00001"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b
    • UID = "4215e9a92c8f40eeb87f47e25dd1ca6b"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b
    • DP = "51"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b\Settings
    • InstallPath = "%Program Files%\DNS Unlocker"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • Inno Setup: Setup Version = "5.5.5 (a)"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • Inno Setup: App Path = "%Program Files%\DNS Unlocker"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • InstallLocation = "%Program Files%\DNS Unlocker"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • Inno Setup: Icon Group = "DNS Unlocker"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • Inno Setup: User = "Wilbert"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • Inno Setup: Language = "english"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • DisplayName = "DNS Unlocker version 1.4"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • UninstallString = "%Program Files%\DNS Unlocker\unins000.exe "
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • QuietUninstallString = "%Program Files%\DNS Unlocker\unins000.exe /SILENT"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • DisplayVersion = "1.4"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • Publisher = "www.dnsunlocker.com"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • NoModify = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • NoRepair = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • InstallDate = "20160112"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • MajorVersion = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{E1527582-8509-4011-B922-29E3FB548882}_is1
    • MinorVersion = "4"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\ROOT\Certificates\26D9E607FFF0C58C7844B47FF8B6E079E5A2220E
    • Blob = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\5da059a482fd494db3f252126fbc3d5b
    • status = "1"

Step 4

Search and delete these components

[ Learn More ]
There may be some components that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %User Temp%\is-b4thv.tmp\{malware file name}.tmp
  • %User Temp%\is-GFV3R.tmp\_isetup\_shfoldr.dll
  • %User Temp%\is-GFV3R.tmp\ConsoleApplication1.dll
  • %User Temp%\is-GFV3R.tmp\config_tmp.ini
  • %Program Files%\DNS Unlocker\unins000.dat
  • %Program Files%\DNS Unlocker\is-IQEB6.tmp
  • %Program Files%\DNS Unlocker\is-BH9O5.tmp
  • %Program Files%\DNS Unlocker\is-40728.tmp
  • %Program Files%\DNS Unlocker\is-0B730.tmp
  • %Program Files%\DNS Unlocker\is-NQIE0.tmp
  • %Program Files%\DNS Unlocker\is-4GB98.tmp
  • %Program Files%\DNS Unlocker\is-0MG6L.tmp
  • %Program Files%\DNS Unlocker\is-FGS3U.tmp
  • %Program Files%\DNS Unlocker\is-4H09L.tmp
  • %Program Files%\DNS Unlocker\is-JQ86F.tmp
  • %Program Files%\DNS Unlocker\is-MRMNO.tmp
  • %Program Files%\DNS Unlocker\is-JCAKC.tmp
  • %Program Files%\DNS Unlocker\is-PSE2S.tmp
  • %Program Files%\DNS Unlocker\is-5577I.tmp
  • %Program Files%\DNS Unlocker\is-REKC9.tmp
  • %Program Files%\DNS Unlocker\is-H6B63.tmp
  • %Windows%\Tasks\DNSPARISH.job
  • %Program Files%\DNS Unlocker\settings.ini

Step 5

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %User Temp%\is-B4THV.tmp
  • %User Temp%\is-GFV3R.tmp
  • %User Temp%\is-GFV3R.tmp\_isetup
  • %Program Files%\DNS Unlocker

Step 6

Scan your computer with your Trend Micro product to delete files detected as PUA_DNSUnlocker. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.

Step 7

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %Program Files%\DNS Unlocker\dnsparish.exe
  • %Program Files%\DNS Unlocker\ZonaTools.XPlorerBar.dll
  • %Program Files%\DNS Unlocker\Microsoft.Win32.TaskScheduler.dll
  • %Program Files%\DNS Unlocker\Info.rtf
  • %Windows%\Tasks\Temp{8702343a-e112-4b32-bde9-65d01e3bd548}.job

Step 8

Restore these deleted registry keys/values from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall
    • {E1527582-8509-4011-B922-29E3FB548882}_is1


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