Read the Cyber Security: Tracking the Current Threat Landscape guide to learn more about how hackers can breach your security and what to be on the lookout for.

Cyber-attacks are a cat-and-mouse game in which the cats are particularly devious—and become more so every time you get wise to their latest tricks. WannaCrypt (or WannaCry, as it became known) was ransomware that invaded computers or servers, seized all their data, and made the data inaccessible to the owners until they paid ransom—in this case, in the form of Bitcoin currency. Any time you’re online, threats exists, including:

• Ransomware. FBI crime statistics show that the number of ransomware attacks increased by a third from 2014 to 2015. Complaints filed grew from 1,800 to 2,400, and losses rose from $23 million to $24 million. But that’s just reported attacks. According to the Bureau’s 2016 Internet Crime Report, victim losses to cybercrime for the year totaled $1.33 billion. Ransomware has the potential to be more effective against businesses with poor IT practices.

• Website attacks. Here, hackers seek vulnerabilities in major tools such as WordPress. In these cases, you may be targeted via email, by someone scraping your site, or by bot-generated attempts to reset your password.

• Email. Among the most familiar schemes are those involving email, where you should be suspicious of anything you see coming in via email that looks in the least bit out of the ordinary. Examples include “we couldn’t deliver your package” notifications when you weren’t expecting a package. Another red flag: a message that appears to be from someone but contains uncharacteristic errors in spelling or grammar. Approach shortened URLs with caution, too, as they’re useful for hiding malware evidence. And if you’ve received something that appears to be spam and includes an “unsubscribe” link, look before you click, because that link may duplicate the sales URL you took care not to click.

PDFs and Word documents can also be infected, because they’re created with programming languages that can be embedded with malware. When you open the document, you unwittingly trigger the execution of a code or launch an application.