In the two previous parts of this series of blog posts, we discussed the kinds of threats that we’re seeing on Twitter, as well as the scope and scale of these threats. In this part, we will discuss their motivations, and what end users can do.
The first question is: why do cybercriminals bother doing this? Social media accounts are valuable in their own right. These accounts can typically be used to make money in many ways for cybercriminals; any form of personally identifiable information (PII) can be monetized by attackers.
One way that stolen social media accounts are used is to send spam. One reason that social media spam can be considered superior to email spam is simple: more people click on links from social media than email. The click-through rate for email spam is estimated at anywhere from 0.003% to 0.02%. How does Twitter spam fare?
It’s difficult to exactly compare numbers for the effectiveness of Twitter spam with those for e-mail spam. One measure we can use is the number of clicks we saw for every spammed Tweet. This varies depending on the type of abuse. Some Twitter spam campaigns could be spectacularly successful: one viral campaign aimed at Japanese users had a 0.269 clicks per Tweet. However, more typical rates varied from 0.01 clicks per Tweet for Twitter-specific spam to 0.03 for malware-linked Tweets. These numbers suggest that Twitter spam is more effective than conventional email spam.
So now we’ve established that Twitter spam is a legitimate threat. How is Twitter responding? We are happy to say that this is a problem Twitter is getting on top of. Earlier this year, they disclosed the existence of BotMaker, their anti-spam bot infrastructure which has cut the spam problem by 40%. Other social networks can study Twitter as an example in how to deal with threats on their sites.
For users, the lessons are clearer. First of all, do not believe any claims that you can buy followers/views/likes/friends/etcetera. The numbers you buy will almost certainly come from compromised accounts. This will bring no, or even negative value, towards your own social media efforts. Your own account may also be compromised in the process. Shortcuts to social media popularity don’t exist.
Secondly, you should already be careful about clicking on links posted on social media in general, but be particularly careful about links that say that you have to log in again because your original log in timed out. Close your browser and start again; if you see the same message it’s almost certainly a phishing page.
Lastly, if the social media services you use support it, turn on two-factor authentication. Just about all large online services today offer some support for two-factor authentication. Turning it on makes compromising your account much harder, as an attacker has to somehow compromise your phone as well. It’s not impossible – other Trend Micro research has shown how this can be done with online banking. However, it is still a useful security precaution to take against most attacks targeting social media.