This attack could pose a serious security threat. You should take immediate action to stop any damage or prevent further damage from happening.
This signature detects the activity of Yes exploit tool kit which result in the download of malicious exploits that may compromise the target computer.
The YES toolkit is a common set of code being hosted on websites used to compromise the downloading host. Toolkits are known to download additional files and malicious content to further infect the host and collect user information. It is recommended to use cautious when visiting unknown websites as they may contain such infected code.
Update all vendor patches to the latest version.