McAfee > Theat Center > Virus Detail Page

Overview

This is a trojan detection. Unlike viruses, trojans do not self-replicate. They are spread manually, often under the premise that they are beneficial or wanted. The most common installation methods involve system or security exploitation, and unsuspecting users manually executing unknown programs. Distribution channels include email, malicious or hacked web pages, Internet Relay Chat (IRC), peer-to-peer networks, etc.

Aliases

• Unix/Sendmail-ADM

Characteristics

This threat was given a Low-Profiled risk assessment due to media attention.

This backdoor is deployed by a trojanized version of sendmail 8.12.6. See advisory for details.

This trojanized version has a modified /libsm/t-shm.c file which, upon execution, decodes and drops a script named test. The script drops a backdor file, conftest.c, compiles it naming the binary as the user shell (sh,csh,bash,tsh,zsh), grabbing this parameter directly from /etc/passwd, and runs it. Finally, the script cleans, in part, the trojanized t-shm.c and exits.

The backdoor forks and opens a connection with 66.37.138.99 port 6667 listening for commands on this socket. The only accepted commands are

• Exit the trojan deamon
• Open a remote shell
• Sleep for 1 hour

Symptoms

• PGP signature of the sendmail sources do not match with the one available on the web.
• Abnormal shell process running.
• Timestamp of the /libsm/t-shm.c file exactly matches /etc/motd.

Method of Infection

This backdoor is dropped by a trojanized version of sendmail.

Removal

All Users :
Use specified engine and DAT files for detection and removal. Delete files which contain this detection.

Additional Windows ME/XP removal considerations

Variants

Variants

N/A

All Information

Overview -

This is a trojan detection. Unlike viruses, trojans do not self-replicate. They are spread manually, often under the premise that they are beneficial or wanted. The most common installation methods involve system or security exploitation, and unsuspecting users manually executing unknown programs. Distribution channels include email, malicious or hacked web pages, Internet Relay Chat (IRC), peer-to-peer networks, etc.

Aliases

• Unix/Sendmail-ADM

Characteristics

Characteristics -

This threat was given a Low-Profiled risk assessment due to media attention.

This backdoor is deployed by a trojanized version of sendmail 8.12.6. See advisory for details.

This trojanized version has a modified /libsm/t-shm.c file which, upon execution, decodes and drops a script named test. The script drops a backdor file, conftest.c, compiles it naming the binary as the user shell (sh,csh,bash,tsh,zsh), grabbing this parameter directly from /etc/passwd, and runs it. Finally, the script cleans, in part, the trojanized t-shm.c and exits.

The backdoor forks and opens a connection with 66.37.138.99 port 6667 listening for commands on this socket. The only accepted commands are

• Exit the trojan deamon
• Open a remote shell
• Sleep for 1 hour

Symptoms

Symptoms -

• PGP signature of the sendmail sources do not match with the one available on the web.
• Abnormal shell process running.
• Timestamp of the /libsm/t-shm.c file exactly matches /etc/motd.

Method of Infection

Method of Infection -

This backdoor is dropped by a trojanized version of sendmail.

Removal -

Removal -

All Users :
Use specified engine and DAT files for detection and removal. Delete files which contain this detection.

Additional Windows ME/XP removal considerations

Variants

Variants -

N/A