BKDR_TAILDR.A
Backdoor.Win32.Agent.dppz (Kaspersky)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It connects to a website to send and receive information.
TECHNICAL DETAILS
589,312 bytes
EXE
Yes
26 Jun 2018
Arrival Details
This Backdoor 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 Backdoor drops the following files:
- %User Temp%\Cab{Random alphanumeric characters}.tmp
- %User Temp%\Tar{Random alphanumeric characters}.tmp
(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.)
Other System Modifications
This Backdoor adds the following registry entries as part of its installation routine:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyServer = http="127.0.0.1:8888https=127.0.0.1:8888"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyOverride = "<-loopback>"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyEnable = "1"
(Note: The default value data of the said registry entry is "0".)
Backdoor Routine
This Backdoor connects to the following websites to send and receive information:
- https://api.{BLOCKED}xapi.com/2/files/delete
- https://content.{BLOCKED}xapi.com/2/files/upload
- https://content.{BLOCKED}xapi.com/2/files/download
SOLUTION
9.850
14.328.06
20 Jun 2018
14.329.00
21 Jun 2018
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
Identify and terminate files detected as BKDR_TAILDR.A
- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 4
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\Internet Settings
- ProxyServer = ”http=127.0.0.1:8888https=127.0.0.1:8888”
- ProxyServer = ”http=127.0.0.1:8888https=127.0.0.1:8888”
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- ProxyOverride = ”<-loopback>”
- ProxyOverride = ”<-loopback>”
Step 5
Restore this modified 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\Internet Settings
- ProxyEnable = "0"
- ProxyEnable = "0"
Step 6
Search and delete this file
- %User Temp%\Cab{Random alphanumeric characters}.tmp
- %User Temp%\Tar{Random alphanumeric characters}.tmp
Step 7
Scan your computer with your Trend Micro product to delete files detected as BKDR_TAILDR.A. 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 the following Trend Micro Support pages for more information:
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