A malicious spreadsheet has been discovered that builds a PowerShell command from individual pixels in a downloaded image of Mario from Super Mario Bros. When executed, this command will download and install malware such as the Ursnif banking Trojan. This attack works when recipients receive an email targeting people from Italy that pretends to be payment notices. The image below has been slightly modified so that it cannot be used for malicious purposes. As always, it is is very important to be careful when it comes to attachments as they are a heavily used method to distribute malware.
Source: https://www.bleepingcomputer.com/news/security/mail-attachment-builds-malware-downloader-from-super-mario-image/