RTKT_ZACCESS.CHA

 Analysis by: Erika Bianca Mendoza

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW


This Trojan may be downloaded by other malware/grayware/spyware from remote sites. It may be dropped by other malware. It arrives as a component bundled with malware/grayware packages.

  TECHNICAL DETAILS

File Size:

163,840 bytes

File Type:

SYS

Memory Resident:

Yes

Initial Samples Received Date:

04 Aug 2011

Arrival Details

This Trojan may be downloaded by other malware/grayware/spyware from remote sites.

It may be dropped by other malware.

It arrives as a component bundled with malware/grayware packages.

NOTES:
This is Trend Micro's detection for ZeroAccess rootkit component. Once running, it checks if its service name starts with '.', if not, it will not continue. It then searches for the registry below and deletes it:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\root\LEGACY_{service name}

It creates a hidden device where it stores its components, thus effectively hiding the files:

  • \\??\\ACPI#PNP0303#2&da1a3ff&0\

This rootkit implements IRP hooking for its stealth routine. It monitors its selected (patched) driver and shows the original copy if it is being accessed or read.

  SOLUTION

Minimum Scan Engine:

8.900

FIRST VSAPI PATTERN FILE:

8.334.07

FIRST VSAPI PATTERN DATE:

05 Aug 2011

VSAPI OPR PATTERN File:

8.335.00

VSAPI OPR PATTERN Date:

06 Aug 2011

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

Scan your computer with your Trend Micro product and note files detected as RTKT_ZACCESS.CHA

Step 3

Identify and delete files detected as RTKT_ZACCESS.CHA using the Recovery Console

[ Learn More ]

Step 4

Search and delete the file detected as RTKT_ZACCESS.CHA

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files in the search result.

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as RTKT_ZACCESS.CHA. 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.

Related Web Attack