Adobe has issued an emergency patch in response to a vulnerability in its popular Flash browser plugin that it said was being used in phishing attacks and other attempts to take over victims’ computers.

The company issued a brief advisory in response to a tip from security firm FireEye, which had noticed the Flash vulnerability being exploited by cybercriminals in phishing schemes in a number of industry sectors. According to ZDNet, companies in tech and telecom, aerospace and construction were targeted. Adobe said people using Firefox and Windows XP, as well as users running Windows 7 and its Internet Explorer browser, are among those at risk of the bug, known as CVE-2015-3113.

Besides phishing schemes, Computerworld said the Adobe Flash vulnerability lets attackers install Shotput or CookieCutter, Internet backdoor programs that can open up corporate networks to prying eyes. Like other sophisticated attack vectors, though, cybercriminals appear to be making regular changes to the infrastructure that runs CVE-2015-3113’s command-and-control (C&C) capability. In other words, if you don’t patch quickly, it could be increasingly difficult to keep track of this exploit as it spreads.

As eWEEK pointed out, this is not the first time Adobe has had to address zero-day threats for Flash. There were multiple reports in February about Flash malware samples growing by more than 300 percent, making it a particularly high-risk piece of technology. The fact that Flash is so pervasive across desktops for a variety of video and multimedia applications probably accounts for it becoming a hot target for cybercriminals.

Experts told IT PRO that the volume of security issues facing Adobe Flash might lead some users to decide to do away with the plugin completely, while others suggested the most recent exploit just proves how vulnerable Internet content is in general.

Forbes suggested the Adobe Flash vulnerability exploits may be traced to a criminal collective known as APT3, which has also leveraged flaws in Internet Explorer. Until more details are confirmed, however, it’s best that anyone using Flash start monitoring for threats as often as they update the software itself.