Lightning strike. A lightning strike is an electric discharge between the atmosphere and an earth-bound object. They mostly originate in a cumulonimbus cloud and terminate on the ground, called cloud to ground (CG) lightning.
Virus protection software is designed to prevent viruses, worms and Trojan horses from getting onto a computer as well as remove any malicious software code that has already infected a computer. Most virus protection utilities now bundle anti-spyware and anti-malware capabilities to go along with anti-virus protection.
A computer virus is a program written to enter your computer system surreptitiously and infect it by installing or modifying files or establishing itself in memory. Some viruses are benign and won't harm your system, while others are destructive and can damage or destroy your data.