The worm checks if it is already running each time it is run. It then copies itself to the system folder under a random name and adds a registry value so it runs at Windows startup. It may also drop a .dll component that is registered as a Browser Helper Object and collects information entered by the user in web pages.
The worm creates a keylogger thread and adds data to a report file created under the System folder with a random name and a .dll extension. It connects to an internet site (common among variants) where it uploads files and collected data. It can also download files from that internet site. The worm can collect a lot of information about the system it is running on and the user that is logged on, such as cached passwords in Internet Explorer and Outlook Express as well as email accounts information.
The worm can copy itself to network shares (and therefore spread on other computers). Only certain versions of the worm include the mass-mailing component.
The worm collects email addresses from various files on the hard disk and sends mails to those addresses. The mail may contain the worm executable as an attachment or a link to a web page where the worm can be downloaded from. The sender of the mail is spoofed. Sometimes it uses the current user (the data is taken from the Outlook account) and sometimes an address found on the local hard disk. The worm uses its own SMTP client implementation. Some versions implement status reporting on the mass-mailer through the backdoor component.
The backdoor component can receive various commands to perform various actions such as upload and download files, create and terminate processes, upload system and user information, disable windows firewall, list folder components and even upload some of the files to the server.
There are no readily apparent indications of infection with Win32/Eyeveg.
Take the following steps to help prevent infection on your computer:
Enable a firewall on your computer.
Get the latest computer updates for all your installed software.
Use up-to-date antivirus software.
Limit user privileges on the computer.
Use caution when opening attachments and accepting file transfers.
Use caution when clicking on links to webpages.
Avoid downloading pirated software.
Protect yourself against social engineering attacks.
Use strong passwords.
Enable a firewall on your computer
Use a third-party firewall product or turn on the Microsoft Windows Internet Connection Firewall.
Get the latest computer updates
Updates help protect your computer from viruses, worms, and other threats as they are discovered. It is important to install updates for all the software that is installed in your computer. These are usually available from vendor websites.
You can use the Automatic Updates feature in Windows to automatically download future Microsoft security updates while your computer is on and connected to the Internet.
Use up-to-date antivirus software
Limit user privileges on the computer
Starting with Windows Vista and Windows 7, Microsoft introduced User Account Control (UAC), which, when enabled, allowed users to run with least user privileges. This scenario limits the possibility of attacks by malware and other threats that require administrative privileges to run.
You can configure UAC in your computer to meet your preferences:
Use caution when opening attachments and accepting file transfers
Exercise caution with email and attachments received from unknown sources, or received unexpectedly from known sources. Use extreme caution when accepting file transfers from known or unknown sources.
Use caution when clicking on links to webpages
Exercise caution with links to webpages that you receive from unknown sources, especially if the links are to a webpage that you are not familiar with, unsure of the destination of, or suspicious of. Malicious software may be installed in your computer simply by visiting a webpage with harmful content.
Avoid downloading pirated software
Threats may also be bundled with software and files that are available for download on various torrent sites. Downloading "cracked" or "pirated" software from these sites carries not only the risk of being infected with malware, but is also illegal. For more information, see 'The risks of obtaining and using pirated software
Protect yourself from social engineering attacks
While attackers may attempt to exploit vulnerabilities in hardware or software to compromise a computer, they also attempt to exploit vulnerabilities in human behavior to do the same. When an attacker attempts to take advantage of human behavior to persuade the affected user to perform an action of the attacker's choice, it is known as 'social engineering'. Essentially, social engineering is an attack against the human interface of the targeted computer. For more information, see 'What is social engineering?
Use strong passwords
Attackers may try to gain access to your Windows account by guessing your password. It is therefore important that you use a strong password – one that cannot be easily guessed by an attacker. A strong password is one that has at least eight characters, and combines letters, numbers, and symbols. For more information, see http://www.microsoft.com/protect/yourself/password/create.mspx