Beware Skype users - A flaw in Skype for Business enables hackers to launch a DoS attack against the platform by sending large numbers of emojis on the instant messaging client. (btw, latest patch/ proper privacy settings can fix this)

When receiving about 800 kittens at once, your Skype for Business client will stop responding for a few seconds. If a sender continues sending emojis your Skype for Business client will not be usable until the attack ends


Any lack of control over users (such as allowing anyone to sign up for the service, rather than specifically authorising each applicant) opens up the messaging system to a range of what are effectively ‘insider’ vulnerabilities."

https://www.scmagazineuk.com/emoji-tsunami-dos-skype-business/article/1518921