Promail.Trojan

SUMMARY

The Promail.Trojan is a Trojan Horse. This trojan allows anyone with access to the anonymous email address mailbox to check, delete, and read your POP mail.

The Promail.Trojan is a full function POP client which allows you to obtain your email from your designated POP server(s). However, in addition to the documented functions, the program also sends your account information including your password to an anonymous email address.

The program Promail has been widely distributed on freeware and shareware repositories. The file is generally distributed as a zip file named proml121.zip. This program is touted as a completely free POP client that provides many standard email client functions. This zip file uncompresses into the file promail.exe. This is the executable that provides POP client services. These POP client services include the ability to retrieve mail from multiple POP servers.

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Easy

Damage

• Damage Level: Low

Distribution

• Distribution Level: Low
• Target of Infection: Windows

TECHNICAL DETAILS

Each time one configures new POP account information in the client, the client creates a file called promail.pml in the Promail program directory. This is a zero byte file. The next time Promail is started and mail is checked, Promail verifies the existence of the promail.pml file. If this file exists, in addition to checking for mail, Promail sends all POP account information (including the password) of each account setup with Promail to an anonymous email address. The host administrators have been contacted about this email account.

This type of data export may compromise your system. This data export will allow the author or anyone with access to the anonymous email address mailbox to check, delete, and read your POP mail.

To fix this threat, one should discontinue the use of Promail. Promail should be uninstalled or all Promail files should be deleted.

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
• Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
• Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.

REMOVAL

Norton AntiVirus users can protect themselves from this trojan horse by downloading the current virus definitions