Everyday is a zero day T-shirt
A zero-day (also known as zero-hour or 0-day or day zero) vulnerability is an undisclosed computer-software vulnerability that hackers can exploit to adversely affect computer programs, data, additional computers or a network. It is known as a “zero-day” because it is not publicly reported or announced before becoming active, leaving the software’s author with zero days in which to create patches or advise workarounds to mitigate its actions.
Attacks employing zero-day exploits are often attempted by hackers before or on the day that notice of the vulnerability is released to the public; sometimes before the author is aware or has developed and made available the corrected code. Zero-day attacks are a severe threat.
Malware writers can exploit zero-day vulnerabilities through several different attack vectors. Sometimes, when users visit rogue websites, malicious code on the site can exploit vulnerabilities in Web browsers. Web browsers are a particular target for criminals because of their widespread distribution and usage. Cybercriminals can also send malicious e-mail attachments via SMTP, which exploit vulnerabilities in the application opening the attachment. Exploits that take advantage of common file types are numerous and frequent, as evidenced by their increasing appearances in databases like US-CERT. Criminals can engineer malware to take advantage of these file type exploits to compromise attacked systems or steal confidential data. Zero Day tshirt, 0day tshirt, exploit tshirt