TSPY_ZBOT.YUYADI
W32/Zbot.ABV!tr.spy (Fortinet), Trojan-Spy.Win32.Zbot.kth (Kaspersky), PWS:Win32/Zbot (Microsoft), Win32/Spy.Zbot.ABV trojan (ESET-NOD32)
Windows
Threat Type: Spyware
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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 the Internet Explorer Zone Settings.
It deletes the initially executed copy of itself.
TECHNICAL DETAILS
314,368 bytes
, EXE
Yes
21 May 2015
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:
- %Start Menu%\Programs\Accessories\{random filename 1}.exe
(Note: %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu 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 files:
- %Application Data%\Microsoft\Network\Connections\Pbk\_hiddenPbk\{random filename 2}.{random extension 1}
- %Application Data%\Microsoft\Network\Connections\Pbk\_hiddenPbk\{random filename 3}.{random extension 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.)
Other System Modifications
This spyware adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
{random key 1}
HKEY_CURRENT_USER\Software\Microsoft\
{random key 2}
HKEY_CURRENT_USER\Software\Microsoft\
{random key 3}
HKEY_CURRENT_USER\Software\Microsoft\
{random key 4}
HKEY_CURRENT_USER\Software\Microsoft\
{random key 5}
HKEY_CURRENT_USER\Software\Microsoft\
{random key 6}
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
{random key 1}
{random value} = "{hex value}"
Web Browser Home Page and Search Page Modification
This spyware modifies the Internet Explorer Zone Settings.
Other Details
This spyware connects to the following possibly malicious URL:
- http://{BLOCKED}ogyincorp.com/server1/xxx2.jpg
It deletes the initially executed copy of itself
SOLUTION
9.750
11.684.08
23 May 2015
11.685.00
23 May 2015
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
- {random key 1}
- {random key 1}
- In HKEY_CURRENT_USER\Software\Microsoft
- {random key 2}
- {random key 2}
- In HKEY_CURRENT_USER\Software\Microsoft
- {random key 3}
- {random key 3}
- In HKEY_CURRENT_USER\Software\Microsoft
- {random key 4}
- {random key 4}
- In HKEY_CURRENT_USER\Software\Microsoft
- {random key 5}
- {random key 5}
- In HKEY_CURRENT_USER\Software\Microsoft
- {random key 6}
- {random key 6}
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\{random key 1}
- {random value} = "{hex value}"
- {random value} = "{hex value}"
Step 6
Search and delete this file
- %Application Data%\Microsoft\Network\Connections\Pbk\_hiddenPbk\{random filename 2}.{random extension 1}
- %Application Data%\Microsoft\Network\Connections\Pbk\_hiddenPbk\{random filename 3}.{random extension 2}
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.YUYADI. 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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