New Delhi: A computer worm targetting Microsoft Windows operating system was detected in computers approximately 220 million times across the world in the past two and a half years, a report said Thursday.
"The Conficker worm was detected approximately 220 million times worldwide in the past two and a half years, making it one of the biggest ongoing threats to enterprises," Microsoft Security Intelligence Report volume 12 (SIRv12) said.
A computer worm is a standalone malware computer programme that replicates itself in order to spread to other computers.
The worm continues to spread because of weak or stolen passwords and infections exploited vulnerabilities, the report added.
"92 percent of Conficker infections were a result of weak or stolen passwords, and 8 percent of infections exploited vulnerabilities for which a security update exists," the report said.
In the fourth quarter of 2011 alone, Conficker was detected on 1.7 million systems worldwide.
"Conficker is one of the biggest security problems we face, yet it is well within our power to defend against," Microsoft Trustworthy Computing Director Tim Rains said, adding, it is critically important for the organisations to focus on the security fundamentals.
Quarterly detections of the Conficker worm have increased by more than 225 percent since the beginning of 2009, the report said.
It was also found out that many of the threats often referred to as Advanced Persistent Threats (APTs) are no more advanced or sophisticated than other types of attacks.
"In most cases, these attacks leverage known vectors such as exploiting weak or stolen passwords, but their success lies in the persistence and determination in trying different tactics to compromise the target," it said.
In order to protect the systems, Microsoft recommends using strong passwords, keeping the systems up to date, using antivirus software from a trusted source and consider the cloud as a business resource.