As an example, Zscaler noted that Adobe Reader has been a prime target for toolkit attacks.
The most broadly installed browser plug-ins are Adobe Flash, with an install base of 96.02 percent; Windows Media Player, with an install base of just around 90 percent; Adobe Reader, at around 88 percent; Microsoft Outlook, at 87.6 percent; and Microsoft .Net, at slightly over 87 percent.
The list of installed yet outdated (unpatched) plug-ins is strikingly different, however. Zscaler observed that around 61 percent of all Adobe Reader installations in the enterprise were outdated. Second was Adobe Shockwave, at around 52 percent. Microsoft Silverlight ranked third, at around 41 percent, while QuickTime was fourth, at just over 19 percent.
Why do Microsoft extensions rank highly among the most installed but lowest among the unpatched, aside from Silverlight? The trend "suggests that enterprises are doing a good job of enforcing operating system updates (i.e. Windows Update), which includes updates to these components, [but they] have yet to get a handle on managing the updating of third-party software and components."
Insecure browers and plug-ins aside, Zscaler pointed to botnets -- which can infect systems to download more malware, send spam, steal credentials, or launch DoS attacks -- as the most prevalent threat to enterprises, ranked by most Web transactions. In the month of the December, Zscaler observed, botnet transactions accounted for nearly 80 percent security blocks. Malicious URLs were a distant second at around 14 percent.
This story, "Internet Explorer losing enterprise traction," was originally published at InfoWorld.com. Get the first word on what the important tech news really means with the InfoWorld Tech Watch blog. For the latest developments in business technology news, follow InfoWorld.com on Twitter.