The Caz virus stays resident and infects COM and EXE files as they are executed.
If a file called CLEAN.* is executed, the virus will display the following text:
Virus anti-McAfee v1.0 (C) SEPTEMBER 1991 Made in SPAIN
After this the virus tries to overwrite data on the hard drive.
The Caz viruses are not common at all.
Some McAfee SCAN versions had false 'ZARAGOZA' alarms in all files protected with F-XLOCK utility. F-CHECK and INSTALL from F-Secure are examples of such files.