As many as 200,000 systems connected to the Internet could be hijacked by hackers exploiting bugs in Symantec's pcAnywhere, including up to 5,000 running point-of-sale programs that collect consumer credit card data, a researcher said today.
The revelations came just four weeks after Symantec took the unprecedented step of telling pcAnywhere users to disable or uninstall the program because attackers had obtained the remote access software's source code.
Several days later, Symantec said it had patched all the known vulnerabilities in pcAnywhere, but declined to declare that the product was safe to use.
According to Rapid7, which prowled the Web looking for pcAnywhere systems, an estimated 150,000-to-200,000 PCs are running an as-yet-unpatched copy of the Symantec software, and are thus vulnerable to be hijacked by remote attacks, which could commandeer the machine's keyboard and mouse, and view what's on the screen.
About 2.5% of those vulnerable Windows PCs, or between 3,450 and 5,000 systems, are running a point-of-sale system -- Windows PCs are often paired with cash registers by small businesses -- potentially putting credit card data at risk, said HD Moore, chief security officer at Rapid7.
Moore reached those conclusions by scanning the Internet for the TCP port the software leaves open for incoming commands, running more targeted scans for evidence of the remote access software, then using the number of programs that identify themselves as older than the patched editions to estimate the extent of the problem.
Some of the computers returned queries with replies consistent with specific point-of-sale software, Moore said.
Point-of-sale software often relies on pcAnywhere for remote support, not for transmitting credit card data, but by exploiting pcAnywhere, a cyber criminal could control the machine and easily harvest the information. "These [point-of-sale] systems are an attractive target for break-in," said Moore.
Previously, Symantec declined to comment when asked how many machines ran its pcAnywhere software, so it's unclear what percentage of all installations are vulnerable.
But Moore sees it as a big problem. "There are a lot [of PCs] that haven't been updated," he said. "It seems the recent patches have been very much ignored."
And it will likely get worse before it gets better.
Last week, Johnathan Norman, director of security research at Texas-based Alert Logic, posted proof-of-concept code that crashes any copy of pcAnywhere, even those that have been recently patched.
While Moore said that Norman's code conducts a denial-of-service attack that results in a crash and automatic restart of pcAnywhere, there may be a way to exploit the DoS to hijack the software. "Where there's smoke there's fire," said Moore.
DoS attacks can sometimes be leveraged to execute remote code.
The source code leak also ups the risk to pcAnywhere users, Moore maintained, even though Symantec has patched some flaws. With the source code at their disposal and the software's problems highlighted in the media, researchers on both sides of the law will spend time looking for vulnerabilities, he said. And some of that research may result in new, exploitable bugs.
An anonymous researcher has already published findings from his examination of the pcAnywhere source code. Although his description on the InfoSec Institute website did not claim any new vulnerabilities, he noted that the source code also revealed the workings of LiveUpdate, the Symantec service used to update much of its software, including its consumer antivirus programs, such as Norton Antivirus.
"We now know how their LiveUpdate system works thanks to the included architecture plans and full source code," said the researcher.
Although Symantec did not reply to a request for comment on Moore's research, a company spokesman said the firm "is aware of [Norman's] proof-of-concept code and is investigating the claims."
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed . His email address is firstname.lastname@example.org.