A potentially serious breach was reported last week against San Francisco-based software accounting firm Codecov. Now, hackers have targeted customers of California-based network service provider SonicWall through a previously unknown vulnerability in its email security product.

In a statement released, SonicWall revealed that the vulnerability had been “exploited in the wild,” implying only that hackers had already used the vulnerability to infiltrate target systems, and urged customers to “immediately upgrade” to a version that had patched the hole. Charles Carmakal, senior vice president of Mandiant, an arm of FireEye, commented on the problem, noting that in the case of SonicWall, hackers could have used the vulnerability to easily gain a foothold in the networks of their targets.

For more information see the original story in Reuters