Scams and Spam to Avoid on Facebook
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Security Response in association with: Scams and Spam to Avoid on Facebook Candid Wüest Principal Software Engineer foreword by the Facebook Security Team Foreword Contents At Facebook, we work hard to protect the people that use our service. We in- Foreword ............................................................ 1 vest in equipment, develop proprietary tools, create innovative security fea- Summary ............................................................ 2 tures and devote hundreds of employees around the world to keep you and Introduction ...................................................... 2 your data safe. But we can’t do this alone, which is why we worked on a guide Attack types ....................................................... 2 with our friends at Symantec to educate people on the most prevalent threats Like/share-baiting ........................................ 3 we are seeing and the best ways for users to keep their data safe while online. Like clickjacking ........................................... 4 We process a huge amount of content to protect the people on Facebook – Malicious (iFrame) application ................... 5 every single day we vet over 26 billion pieces of content and 2 trillion link Self-XSS copy/paste attacks ....................... 6 clicks. But with more than 800 million people visiting our site each month Tagging ......................................................... 8 and more than 400 million visiting every day, Facebook has become an Phishing ....................................................... 8 ever more attractive target for spammers and scammers. That’s why more Hoax .............................................................. 9 than three hundred Facebook security engineers and hundreds of user op- Various scams and spams............................ 9 erations personnel work around the clock to keep you and your data safe. Cleaning up ........................................................ 9 Remove the offending posts ........................ 9 By embracing advanced technology, our engineers work to ensure that Remove offending applications ................. 10 using Facebook is a secure experience. We have several internal sys- Change your password ............................... 10 tems to discover, disarm, and disable threats. However, not all the secu- Settings guide .................................................. 10 rity mechanisms operate behind the scenes and we want to empower ev- Privacy settings .......................................... 11 eryone to control their Facebook experience by using the power of social Account settings ........................................ 12 connections to keep you and your data safe on the site. Some of these Conclusion........................................................ 13 are on for everyone by default, and others allow people to choose what level of security best fits their lifestyle. We encourage people to visit the Facebook Security Page or our Help Center to learn about these tools. But even with all of these resources, we still need your help to keep our site safe. We all have a part to play in keeping the Web safe, and making sure we only click or share links we trust is a huge part of that. Please read the guide and let your friends know what you’ve found out. Thanks again to Symantec for their expertise and efforts in helping keep the people who use Facebook safe. Scams and Spam to Avoid on Facebook Security Response Summary Social networks are an inherent part of today’s Internet. With more than 800 million registered accounts, Face- book is the largest social network in use at the moment. For many people it has become the primary medium for sharing ideas and interacting with friends. It is also becoming a booming attack ground for malware authors and scammers. By taking advantage of the users’ trust in their network of relationships, they are spreading malicious code and sending spam messages. Most of the attacks that we currently see use social engineering tricks to spread their messages to thousands of users. Besides reposting spam messages to friends, this can lead to scam surveys or malicious sites. The following paper will illustrate and discuss the most prevalent issues and threats targeting the Facebook network today, as well as provide help in choosing the right configuration settings. Introduction This paper discusses different aspects of both spam and scam attacks that we have observed in Facebook, rang- ing from advertisement spam to redirecting lures for drive-by malware sites. The focus will be on scams spread- ing in the social network rather than attacks against the framework implementation or privacy leaks. Facebook is working hard to combat these issues, with a dedicated security team focused on eliminating attacks in the social network and their self-created Facebook Immune System (FIS). They are constantly adding new fea- tures and improving security settings. Therefore some of the examples mentioned in this paper no longer work, having been mitigated by such changes. None of the discussed attacks are Facebook-specific, and could happen in a similar form on other social networks. Attack types The attacks usually start with a method to grab the user’s attention. This is often done with a status message update on a friend’s Timeline, direct chat messages, or calendar event invitations. Newer attacks make use of IP geo-location services, bringing in localized context such as the visitor’s city name. Other scams will display your real name and some of your friend’s names to make the bait appear more credible. Clicking the link, or interact- ing with the bait page, leads to another site that contains the payload of the attack. In 2011 Facebook started to use third-party services like the Web of Trust URL reputation service to analyze any direct link leaving the facebook.com domain. This means that if the scam is already well-known and classified, the URI will likely be on Web of Trust’s blacklist and Facebook will warn the user when clicking on it. According to Facebook, they block 220 million messages with malicious links every day. Unfortunately these scams vary the URLs frequently so that often there is no blocking rating for new scams when they first appear. Some of the newer services use heuris- tics to block even previously unknown malicious links, but there will always be some URLs that are not blocked. In order to bypass these filters, we have even seen attackers use cross-site scripting vulnerabilities on trusted domains to forward to malicious pages. Figure 1 The themes meant to trick users are often Outgoing link blocking reused. Popular ones include: • Find out who viewed your profile or de- leted you from their account. • Some shocking video or image of some person or accident. • Get free points for online games or gift cards for various shops. Most attacks discussed here require the user to be logged into his or her account. Since many users are permanently logged into their accounts, or at least of the time when seeing the bait messages, this pre- requisite is usually fulfilled. We encourage users to report spam and scam messages to Facebook through the reporting button. This helps preventing the scams from propagating further. Symantec will also work with Facebook to detect and alert users to potentially malicious URLs on the site, helping to provide a safer experience for members. Page 2 Scams and Spam to Avoid on Facebook Security Response Like/share-baiting Figure 2 Manual Like scam Type: Light social engineering Result: User liking a link This is the most commonly encountered type of scam at the moment. The user is asked to manually like or share the rogue site in order to get access to some promised content. For example, the user has to Like the page before an enticing video is shown. This is the identical behavior that any legit brand site can use as well, so it is very hard to distinguish between malicious and legit use. Obviously the scenarios are endless where the user is asked to Like a page before he or she can participate at a contest or see a video. In the same category is the variation where the mali- cious page asks the user to post a given message at least five times on Facebook before access to the special content is given. Figure 3 Next, the user is often forwarded to a cost-per-action Manual Share and survey request (CPA) survey before the promised content is shown. These surveys are not malicious per-se and can also be used on legitimate sites. Some of the external pages mimic the look and feel of Facebook to increase their credibility. Here the scammers are misusing them, through affiliate services, in order to get clicks or il- licit participation from the user. They often mask the survey as a mandatory “security test”, which they are not. Most of these surveys are free to fill out but might require some personal information to be shared. For every user that fills out a survey the author behind it gets commission money which can be from $0.50–$20, depending on the required work from the user. We have also seen links to ringtone subscription services and similar expensive premium content. Of course normal banner ads can also be used by the attacker to earn money. Figure 4 CPA survey request Page 3 Scams and Spam to Avoid on Facebook Security Response Another variation of this type of scam lures the user with free gift cards for online shops or restaurants. In order to receive the voucher the user is asked to share the site with his or her friends and provide some personal infor- mation. The fine print states that the user has to subscribe to a few sponsored offers in order to get the voucher. Sometimes there actually is a real gift card or voucher involved in the end, but only after expensive subscriptions are accepted. Recommendations: Users should be vigilant when asked to like links or sites in order to get access to some content. When asked to provide personal information or fill out surveys, they should be skeptical and rethink if it is worth the time and risk. Users should be aware that the subscribed services are often not free and that the personal information handed out might be used for further Figure 5 advertisement.