Take the Skype Flooder as an example.
This Skype spamming tool is in its second iteration. It can be bought on underground forums for a mere $10 and, as a bonus, the buyer also receives 5000 already harvested Skype user names.
According to the ad, the flooder allows users to add, search and spam contacts, to harvest Skype user names based a particular country or gender, as well as display information such as city, username and online status. This newest version is also capable of parsing log files.
But there is also good news.
"Since the tool is only capable of spreading a particular message to those who give authorization to the spammer’s account, as well as the fact that it doesn’t support multiple spam accounts and proxies, it doesn’t represent a scalable threat. Instead, it primarily relies on social engineering," Webroot points out.
"Although the tool is capable of segmenting the targeted population for better conversion rate, the user still has to authorize the spammer in order to receive messages from him."
Luckily for Skype users, they can easily protect themselves from random spammers by tweaking their privacy settings and making it impossible to receive calls, videos, screens and IMs from anyone who's not in their Contact list.
They just must then be careful not to add spammy users (accounts) to that list.