Backdoor

“Backdoor” is an alternative access to a software program or computer. A backdoor can be installed by a legitimate software manufacturer in a program, such as to be able to access the program on behalf of a customer, despite a forgotten password. As malware, a backdoor provides cyber criminals access to a computer or network. They can control a computer, lock it, encrypt its data, manipulate or spy on input. Often, a backdoor program gets into the system via a Trojan horse.

What does the term “backdoor” mean in detail?

• Even if a legitimate backdoor in software has practical benefits, it poses a security risk.
• A back doorprogram can be installed with a Trojan horse or hide the fact that it is a Trojan horse. Therefore, security measures to prevent Trojan horses are also helpful against backdoor programs.
• If a Trojan horse has a backdoor program installed, the latter will remain active even when the Trojan horse is detected and removed.
• Even for savvy programmers, finding a backdoor in the software source code can be difficult. True to the principle of many-eyes, open source software is considered to be safer in this respect (but not as safe!), because it is critically reviewed by many programmers.

Where do I encounter backdoors in my daily work?

By opening a fraudulent e-mail attachment, you can unintentionally install a backdoor program on your computer. This may initially go unnoticed, for example, if the program is used to spy on information and password entries, or if it sets up a backdoor for a blackmail attack that occurs later.

What can I do to improve my safety?

Many cyber security measures help prevent the installation of a backdoor program. These include:

• Use of a constantly updated virus program
• Only install software and updates from verified sources. If necessary, bring up the manufacturer’s website manually
• Very critical handling of emails, especially with links and attachments contained therein
• Use a firewall to prevent access to a possible backdoor.