We’re pretty convinced that if Microsoft hasn’t already decided to make an about-face on its decision to officially throw Windows XP into end-of-life status, it’s not going to change its mind in the next 18 days(Opens in a new window).

But, as the saying goes, you miss 100 percent of the shots you don’t take and Avast Software has issued a warning about XP’s demise.

Ondrej Vlcek, Avast’s chief operations officer, took to his company’s blog(Opens in a new window) a few days ago to discuss all of the trends that Avast is seeing — or pondering — as a result of Windows XP losing Microsoft’s support in a few weeks. While he’s not outright calling for Microsoft to reverse its decision, he does, as you might expect, go into a bit of detail about how Avast is working to patch that which Microsoft no longer plans to address.

According to Vlcek, Avast is allegedly seeing data indicating that Windows XP users’ systems will be “six times” more likely to come under attack by third parties than those running Windows 7 – which Microsoft will still be supporting in the near future, obviously.

“The abandonment by Microsoft will not only affect Windows XP users, but will create a big security problem for the whole ecosystem. Tens of millions of PCs running XP connected to the Internet, unpatched and without security updates, are just waiting to be exploited. The vulnerable OS will be an easy target for hackers and be seen as a gateway to infect other non-XP operating systems,” Vlcek writes.

He also cites the oft-mentioned ATM example as an area where the loss of Windows XP critical updates, maintenance, and exploit patches, could be rather disastrous for a fairly critical industry. There are a number of banks that are working at a presumably fast pace to get their systems kicked up to Windows 7 from Windows XP. Others are contracting with Microsoft for additional Windows XP support – a pricey, but potential alternative – roughly $1,000 to $3,500 for each replacement machine, according to CNNMoney(Opens in a new window).

ATMs aren’t the only devices at risk. “Medical offices that store confidential patient information and stores that keep customer details, such as credit card numbers, on their computers running Windows XP could easily be attacked. The Target data breach last year was conducted through a trojan that attacked the shops’ point of sales system. If businesses don’t keep their systems safe, we will, unfortunately, see more of data breaches like this,” Vlcek writes.

For more, check out Killing Windows XP Wastes Billions, as well as PCMag’s review of Microsoft Windows 8.1 and the slideshow above.