TSPY_ZBOT.YYDBZ
PWS:Win32/Zbot (Microsoft); Trojan-Dropper.Win32.Necurs.txz (Kaspersky)
Windows
Threat Type: Spyware
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
Dropped by other malware, Downloaded from the Internet
This spyware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It does not have any propagation routine.
It does not have any backdoor routine.
It steals certain information from the system and/or the user.
It deletes itself after execution.
TECHNICAL DETAILS
202,048 bytes
EXE
Yes
17 Sep 2014
Connects to URLs/IPs
Arrival Details
This spyware 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 spyware drops the following copies of itself into the affected system and executes them:
- %User Temp%\{random folder name}\{random filename 1}.exe
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It drops the following file(s)/component(s):
- %System%\drivers\{random filename 2}.sys - detected as RTKT_NECURS.RBC
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
It drops the following non-malicious files:
- %AppDataLocal%\{random filename 3}.{random extension}
(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local on Windows Vista and 7.)
It creates the following folders:
- %User Temp%\{random folder name}
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- Local\{GUID}
- Global\{GUID}
It injects codes into the following process(es):
- explorer.exe
Autostart Technique
This spyware adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random filename 1} = "%User Temp%\{random folder name}\{random filename 1}.exe"
It registers its dropped component as a system service to ensure its automatic execution at every system startup. It does this by creating the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random filename 2}
DisplayName = "{random filename 1}.exe"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random filename 2}
ErrorControl = "0"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random filename 2}
ImagePath = "\??\%System%\drivers\{random filename 2}.sys"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random filename 2}
Start = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random filename 2}\Security
Security = "{hex value}"
It registers its dropped component as a system service to ensure its automatic execution at every system startup. It does this by creating the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random filename 2}
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random filename 2}\Security
Other System Modifications
This spyware adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
{random}
It creates the following registry entry(ies) to bypass Windows Firewall:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Windows%\explorer.exe = "%Windows%\explorer.exe:*:Enabled:Windows Explorer"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
{random port 1}:UDP = "{random port 1}:UDP:*:Enabled:UDP {random port 1}"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
{random port 2}:TCP = "{random port 2}:TCP:*:Enabled:TCP {random port 2}"
Propagation
This spyware does not have any propagation routine.
Backdoor Routine
This spyware does not have any backdoor routine.
Information Theft
This spyware steals the following information:
- Data on cookie files (URLs)
- Email-related information such as account names, email addresses, passwords, server data, and server port
- Email information stored in the user’s Windows Address Book (WAB) file
- Online banking credentials
- Personal digital cerificate
Stolen Information
This spyware sends the gathered information via HTTP POST to the following URL:
- http://{BLOCKED}wslxpvvphxnjij.biz
- http://{BLOCKED}uzllfeyhcuzddpfafuyp.ru
- http://{BLOCKED}buzttmrciuomjwrcjr.info
- http://{BLOCKED}dmzswgexoqzlfaddqvgjuw.biz
- http://{BLOCKED}nk.fbi-cyber.net
- http://{BLOCKED}rgdqkfdujrfqwkhapbsg.org
- http://{BLOCKED}gytwxwkfbyldaqea.info
- http://{BLOCKED}.{BLOCKED}.4.71
- http://{BLOCKED}.{BLOCKED}.43.69
Other Details
This spyware connects to the following URL(s) to check for an Internet connection:
- http://google.com
- http://bing.com
It deletes itself after execution.
NOTES:
It collects information from certain financial/banking programs that contain the following strings:
- bancline
- bankman
- cruisenet
- dirclt32.exe
- episys
- fastdoc
- fdmaster.exe
- fidelity
- gplusmain
- jack henry
- launchpadshell.exe
- micrsolv
- pcsws.exe
- prologue.exe
- silverlake
- tellerplus
- v48d0250s1
- vantiv
- wtng.exe
It does not have rootkit capabilities.
It does not exploit any vulnerability.
SOLUTION
9.700
11.152.02
16 Sep 2014
11.153.00
17 Sep 2014
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
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Remove malware/grayware files dropped/downloaded by TSPY_ZBOT.YYDBZ. (Note: Please skip this step if the threats listed below have already been removed.)
Step 4
Scan your computer with your Trend Micro product and note files detected as TSPY_ZBOT.YYDBZ
Step 5
Restart in Safe Mode
Step 6
Delete this registry value
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {random filename 1} = "%User Temp%\{random folder name}\{random filename 1}.exe"
- {random filename 1} = "%User Temp%\{random folder name}\{random filename 1}.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- %Windows%\explorer.exe = "%Windows%\explorer.exe:*:Enabled:Windows Explorer"
- %Windows%\explorer.exe = "%Windows%\explorer.exe:*:Enabled:Windows Explorer"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- {random port 1}:UDP = "{random port 1}:UDP:*:Enabled:UDP {random port 1}"
- {random port 1}:UDP = "{random port 1}:UDP:*:Enabled:UDP {random port 1}"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- {random port 2}:TCP = "{random port 2}:TCP:*:Enabled:TCP {random port 2}"
- {random port 2}:TCP = "{random port 2}:TCP:*:Enabled:TCP {random port 2}"
Step 7
Delete this registry key
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\SYSTEM\CurrentControlSet\Services
- {random filename 2}
- {random filename 2}
- In HKEY_CURRENT_USER\Software\Microsoft
- {random}
- {random}
Step 8
Search and delete these folders
- %User Temp%\{random folder name}
Step 9
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.YYDBZ. 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 10
The following created files/folders/registry keys/registry entries cannot be identified by the user since there are no reference values in the created key. The only way it can be identified is by comparing the present system information with a backup. Note that the said components do not have to be deleted since it won't be harmful to the system.
- HKEY_CURRENT_USER\Software\Microsoft\{random}
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