The first worm, Zobot C, is similar to the worms that appeared yesterday, but has been augmented so that it can spread via email by pretending to be a photographic attachment as well as by network sharing. It turns infected machines into part of a remote controlled botnet and is spreading slowly but steadily.
The second, Tilebot-F, is spreading much more quickly and downloads spyware as well as a Trojan allowing remote control of the PC.
"I suspect Tilebot has been written by a different group," said Graham Cluley, senior technology consultant for Sophos.
"It now looks as though separate gangs of virus writers are getting in on the act. It's like a gold rush and everyone is racing to catch the unpatched computers."
Major antivirus vendors have identified signature files and they are available for download and Microsoft is urging all users to patch systems immediately.
Curiosity rover is in 'normal mode' but not transmitting scientific data back to base
NatWest outage comes a day after Barclays' IT systems shut out customers and staff
The ICO is concerned with AggregateIQ's retention and processing of data used in the Brexit referendum
Map selection, quick menus for grenades and healing items, and automatic reload all coming in PUBG update #22