Hi, not likely a virus, & there is minimal protection in 10.5.8 & up...
About Safari 5.1.7 and Leopard Security Update 2012-003
Learn about Safari 5.1.7 and Leopard Security Update 2012-003.
Mac OS X 10.5, Product Security, Safari 5.1 (Mac OS X 10.6), Safari 5.1 (OS X Lion)
Safari 5.1.7 for OS X Lion, Safari 5.1.7 for OS X Snow Leopard, and Leopard Security Update 2012-003 disable out-of-date versions of Adobe Flash Player.
Out-of-date versions of Adobe Flash Player do not include the latest security updates and will be disabled to help keep your Mac secure. If Safari 5.1.7 or Leopard Security Update 2012-003 detects an out-of-date version of Flash Player on your system, you will see a dialog informing you that Flash Player has been disabled. The dialog provides the option to go directly to Adobe's website, where you can download and install an updated version of Flash Player.
If you need to re-enable an out-of-date version of Flash Player, you can do the following:
1. Navigate to the /Library/Internet Plug-Ins (Disabled) folder.
2. Drag "Flash Player.plugin" into /Library/Internet Plug-Ins.
3. If the browser is running, quit and restart it.
If you or her really think she needs it...
ClamXAV, free Virus scanner...
But have her do this first...
Safe Boot from the HD, (holding Shift key down at bootup), run Disk Utility in Applications>Utilities, then highlight your drive, click on Repair Permissions, reboot.
If still problems, then...
See if the Disk is issuing any S.M.A.R.T errors in Disk Utility...
Open Activity Monitor in Applications>Utilities, select All Processes & sort on CPU%, any indications there?
How much RAM & free space do you have also, click on the Memory & Disk Usage Tabs.
Open Console in Utilities & see if there are any clues or repeating messages when this happens.
In the Memory tab of Activity Monitor, are there a lot of Pageouts?
Is there any anti-virus built into OS X 10.5?
As was already indicated, almost none. It does have a Quarantine system which warns users whenever they are about to open a new file for the first time that was downloaded or copied to the hard drive, but there is no check for specific malware. The best thing for her to do would be to upgrade her OS X at least to Snow Leopard which does have additional anti-malware protection.
But as was indicated, it almost certainly isn't malware problem. If you could post a crash report we would be able to tell you what was crashing and where to look for a specific cause.
There are many forms of ‘Malware’ that can affect a computer system, of which ‘a virus’ is but one type, ‘trojans’ another. Using the strict definition of a computer virus, no viruses that can attack OS X have so far been detected 'in the wild', i.e. in anything other than laboratory conditions. The same is not true of other forms of malware, such as Trojans. Whilst it is a fairly safe bet that your Mac has NOT been infected by a virus, it may have another security-related problem, but more likely a technical problem unrelated to any malware threat.
You may find this User Tip on Viruses, Trojan Detection and Removal, as well as general Internet Security and Privacy, useful:
The User Tip (which you are welcome to print out and retain for future reference) seeks to offer guidance on the main security threats and how to avoid them.
More useful information can also be found here: