In January, Incapsula released analysis showing how infected webservers were being used in order to elevate broader attacks, such as DDoS campaigns, which we have recently witnessed targeting the banking industry.
Yesterday, ThreatPost released an article discussing the recent rise of DDoS against US Banks. Some banks were reported to suffer service disruption. This follows a warning issued by the Qassam Cyber Fighters hacktivist group, claiming it will disrupt US Banks operations as part of “Operation Ababil.”
Denial of Service (DoS) attacks are technical attacks that are focused on consuming the resources of a server/service, which prevents it from serving more legitimate users of that specific service. This is done either by consuming the available network bandwidth, or in the application age, by consuming the actual application resources. These attacks usually require many machines addressing the service in the same time to generate the load.
The Web Threat Angle
In the industrialised hacking age, where Hactivism has become talk of the day, hackers build botnets in order to coordinate such an attack from many computers. One of the easiest ways to build a botnet is through “Waterhole” websites, which are popular websites infected with malware that infect the host, which becomes a zombie in the botnet, waiting for instructions to generate targeted traffic upon demand. The recent NBC malware infection attack is a great example of the use of Waterhole websites to infect the masses.
Now we are seeing itsoknoproblemo, which is one of the tools most used in the recent DDoS attacks against the US Banking industry, some peaking at 70 Gbps.
This tool is distributed mostly via a Remote File Inclusion (RFI) attack, creating a drive-by download vector for users that hit the infected web pages, and then become zombies. An RFI attack allows you to plant/redirect users to malicious code just by going on the website.
What Does This Teach Us?
There are two problems that need to be dealt with here. One is the problem that the banks now deal with: the DDoS attacks themselves. The other is the infection vector of the malware via webservers.
The RFI vulnerability is the starting point that allows hackers to build the bot-net that eventually generates the DDoS attack. Since alongside spear-phishing, it enables one of the biggest ways for hackers to send malware and DDoS-specific malware to users.
Interestingly enough, companies protected by Web Application Firewalls are capable of protecting themselves against RFI attacks and from the follow-up of distributing malware. And even though they do not suffer from the DDoS attack itself, the malware distribution creates the reputation damage that companies fear.