Safe computer use is extremely important for your protection and the protection of other systems and users on the network. Unfortunately, for many persons, effectively implementing recommended security controls poses a real problem. Most software and operating systems are not securely configured by default, thus it can be a little overwhelming, even for the most practiced professional, to understand and properly implement myriad effective security controls across different systems, devices and programs. The combination of which makes for secure use, but all too often one or another control is overlooked, thus opening up a hole through which miscreants can then wreak havoc.
Below are some links to information compiled and presented in a format mainly aimed towards the casual computer user, those of us whose primary occupation, hobby, or interests are not related to computing. Of course the linked information is useful to computer experts and other knowledgeable persons as well.
US-CERT has excellent resources to help you secure your system and personal networks
OnGuard Online is another good resource where one can learn to implement recommended best safety and security practices. A few direct links are bullet-pointed below, but you are encouraged to peruse the entire site.
System Trojan and Virus Protection
All systems that ever connect to the Internet should have antivirus software installed on them and the rules kept updated on a daily basis.
Caltech offers Symantec (Norton) AntiVirus for Windows and Macintosh operating systems, free of charge to students, faculty and staff.
- General Virus Information
- Information on Emailed Visual Basic Script (VBS) Viruses
- instructions for changing yWindows default settings to be less vulnerable to viruses.
We also recommend using unprivileged system accounts for every day computing purposes. This is especially important for Windows XP as the default account set up during installatiion has administrative privileges. These privileges facilitate easy injection of system rootkits and other malicious software, mainly through Internet Explorer, Outlook and Adobe Acrobat and Flash applications, which inject code into the root level of the running system preventing detection by the user or installed AntiVirus applications.
System Updates and Patches
All systems, regardless of OS (Linux, Windows, Mac OS X), that connect to the Internet must be kept up to date with the latest operating system and software patches. Update utilities should be set to check for new updates every day. Keep in mind some updates will require a reboot, so plan the update times accordingly.
- Windows users should set WindowsUpdate to run daily as new vulnerabilities in commonly-used programs such as Internet Explorer and Outlook are exploited by virus-writers very quickly.
- Mac OS X users should ensure Software Update runs daily.
- RHEL users should ensure PUP runs daily.
P2P and Windows Messenger
Peer-to-peer filesharing programs such as KaZaA and Gnutella install as servers by default. Protect yourself by changing the default settings on a variety of peer-to-peer filesharing programs, using instructions found here. Covers most P2P applications.
Please be aware that MP3 and other media files can contain malicious content and are vectores for myriad malicious exploit injections.
Please also note that filesharing copyrighted materials of any kind without the copyright holder's permission is a violation of Caltech acceptable use policies. Please refer to the Institute's copyright tutorial for more details.
Windows Messenger can also pose problems, here is some information on preventing Windows Messenger "popup spam" and exploits
Browser and Email Security
Here are some Basic browser security settings
- General information about junk email, a.k.a. "SPAM" and tips for dealing with it.
- The IMSS mail servers use a rule-based program called "SpamAssassin" to flag messages that are probably spam. Using your mail client, you can filter out these messages into a special mailbox, or otherwise tag them for easy removal.
- The IMSS mail servers also run antivirus software that helps prevent viruses from reaching users' inboxes. However that does not mean you think it safe to open every email attachment you receive. Recent and 0-Day exploit rules may not have made it into the AntiVirus ruleset, thus please use common sense when opening any email attachments.
Securing Network Communications
- SSH - Used for encrypted interactive logins to remote systems, a secure replacement for telnet.
- GPG/PGP - Used for email and file encryption to protect sensitive communications.
- VPN - Used to securely connect to the campus network via a remote Internet location.
General User Responsibilities