TSPY_ZBOT.YUYANM
PWS:Win32/Zbot (Microsoft); a variant of Win32/Spy.Zbot.YW trojan (ESET);
Windows

Threat Type: Spyware
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Downloaded from the Internet, Dropped by other malware
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 modifies Internet Explorer security settings. This puts the affected computer at greater risk, as it allows malicious URLs to be accessed by the computer.
It steals certain information from the system and/or the user.
It deletes the initially executed copy of itself.
TECHNICAL DETAILS
192,512 bytes
Yes
20 Jun 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 files:
- %Application Data%\{random folder name 2}\{random file name 2}.{random extension 1}
- %Application Data%\{random folder name 3}\{random file name 3}.{random extension 2}
- %Application Data%\Microsoft\Address Book\{username}.wab
- %Application Data%\Microsoft\Address Book\{username}.wab~
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)
It drops the following copies of itself into the affected system:
- %Application Data%\{random folder name 1}\{random file name 1}.exe
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)
It creates the following folders:
- %Application Data%\{random folder name 3}
- %Application Data%\Microsoft\Address Book
- %Application Data%\{random folder name 1}
- %Application Data%\{random folder name 2}
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- Local\{GUID}
- Global\{GUID}
It attaches itself to all running processes.
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} = "%Application Data%\{random folder name 1}\{random file name 1}.exe"
Other System Modifications
This spyware adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
WAB
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4\Wab File Name
HKEY_CURRENT_USER\Software\Microsoft\
{random key}
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkContactRefresh = "0"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkFolderRefresh = "0"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4\Wab File Name
{Default} = "%Application Data%\Microsoft\Address Book\{user name}.wab"
HKEY_CURRENT_USER\Software\Microsoft\
{random key}
{random} = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
FirstRun = "1"
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"
Web Browser Home Page and Search Page Modification
This spyware modifies Internet Explorer zone settings.
Information Theft
This spyware accesses the following site to download its configuration file:
- http://{BLOCKED}fulmoments.in/3jdfh75hd/mj190f31f.php|file=config.bin
- http://{BLOCKED}collection.in/3jdfh75hd/mj190f31f.php|file=config.bin
- http://{BLOCKED}accounts.in/3jdfh75hd/mj190f31f.php|file=config.bin
It steals the following information:
- FTP credentials
- Internet session cookies
- Flash player data
- Personal certificates
- Video capture
- Keyboard logs
- Clipboard logs
Other Details
This spyware connects to the following URL(s) to check for an Internet connection:
- http://www.google.com/webhp
It deletes the initially executed copy of itself
NOTES:
This spyware queries the system's registry information for the following keys to check for the installed security related software:
- *ROOT\SECURITYCENTER
- *ROOT\SECURITYCENTER2
If found, it avoids injecting on the following processes on the system:
- AntiVir
- avast!
- AVG
- ESET
- Kaspersky
- Microsoft
- Norton
- Symantec
It steals passwords and usernames from cache and cookies of the following browsers:
- Chrome
- Firefox
- Internet Explorer
The configuration file may contain URLs where it downloads an updated copy of itself and where it sends its gathered information. However, as of this writing, the URL where it downloads the configuration file is already inaccessible.
SOLUTION
9.300
12.338.03
12 Feb 2016
12.339.00
13 Feb 2016
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
Restart in Safe Mode
Step 4
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_CURRENT_USER\Software\Microsoft
- WAB
- WAB
Step 5
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} = "%Application Data%\{random folder name 1}\{random file name 1}.exe"
- {random} = "%Application Data%\{random folder name 1}\{random file name 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"
Step 6
Search and delete these folders
- %Application Data%\Microsoft\Address Book
- %Application Data%\{random folder name 1}
- %Application Data%\{random folder name 2}
- %Application Data%\{random folder name 3}
Step 7
Reset Internet security settings
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.YUYANM. 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.
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