BKDR_ZACCESS.BB
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted: No
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 executes then deletes itself afterward.
However, as of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
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 executes then deletes itself afterward.
Other System Modifications
This backdoor adds the following registry keys as part of its installation routine:
HKEY_CLASSES_ROOT\Interface\{91137ba5-45d2-d8ad-576f-6beda9ed3a94}
Other Details
This backdoor connects to the following possibly malicious URL:
- http://{BLOCKED}ur.cn/{BLOCKED}t2.php?w=15&i={random characters}&a=1
- http://{BLOCKED}ur.cn/{BLOCKED}d.php?w=15&fail=1&i={random characters}
- http://{BLOCKED}ur.cn/{BLOCKED}at2.php?w=15&i={random characters}&a=21
- http://{BLOCKED}ur.cn/{BLOCKED}t2.php?w=15&i={random characters}&a=20
However, as of this writing, the said sites are inaccessible.
SOLUTION
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.
- In HKEY_CLASSES_ROOT\Interface
- {91137ba5-45d2-d8ad-576f-6beda9ed3a94}
- {91137ba5-45d2-d8ad-576f-6beda9ed3a94}
Step 3
Scan your computer with your Trend Micro product to delete files detected as BKDR_ZACCESS.BB. 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.
Did this description help? Tell us how we did.