Welcome!

Cloud Security Authors: Zakia Bouachraoui, Pat Romanski, Elizabeth White, Yeshim Deniz, Liz McMillan

Related Topics: Microservices Expo, Cloud Security

Microservices Expo: Blog Feed Post

Turning the Pushdo Bot into the Push-oh-no-you-don’t Bot

Options to put a stop to the latest mutation of the Pushdo trojan

Options to put a stop to the latest mutation of the Pushdo trojan

image The Pushdo bot is a malevolent little beast that is nothing new to Infosec professionals. What might be new, however, is that it recently changed its code and now creates junk SSL connections. Lots of them.

blockquote I mean you are likely seeing an unexpected increase in traffic by several million hits spread out across several hundred thousand IP addresses. No you didn't read that wrong that is millions of hits and hundreds of thousands of IP addresses. This might be a big deal if you're used to only getting a few hundred or thousands of hits a day or you don't have unlimited bandwidth. -- ShadowServer 01/29/2010

Pushdo is usually classified as a "downloader" trojan - meaning its true purpose is to download and install additional malicious software. (SecureWorks, Analysis of a Modern Malware Distribution System) That’s something you definitely don’t want to let loose inside your network, right? So the trick is to recognize its new behavior, somehow, and kick it in the derriere before it can do any real damage or consume resources or leave little bot droppings that might clog up the network pipes.

Luckily, Pushdo has a recognizable pattern: it sends malformed SSL HELLO requests after the TCP connection is established. This means we have several options for dealing with this new variant.


STOPPING PUSHDO

First, you could ignore it. That’s probably asking for trouble but it is an option. The target server will respond to the request with an error because the client hello portion of the SSL handshake is malformed. There’s very little danger in that, it’s expected behavior. However, there’s a distinct possibility that the pattern will change again, potentially by correcting the “malformed” hello so that it is valid and thus making a connection and delivering itself. Having been lulled into ignoring it, it might even succeed. Yes, it could be a social engineering attempt to make you complacent in preparation for a real attack. Miscreants are evil like that, you know, you just can’t trust them.

blockquote The most aggressive pushdo infected hosts appear to establish a connection about once a minute. We identified about 10k host attacking www.sans.org. According to some reports, Pushdo will also just establish a TCP connection, and then just sit without actually sending the SSL Helo message.
ISC SANS Diary

Because the new behavior of Pushdo now has it basically acting like a (fairly ineffective in most cases) DoS, it’s also not a good idea to let the requests get to the server because, well, that means the DoS is successful. If the server is busy responding to Pushdo requests it can’t respond to legitimate requests. In a public cloud computing environment, of course, the consequences can likely be pushdocounted in hard dollars as instances of applications may be launched or continue to remain active throughout the duration of the attack, even though second, third or more instances may not be required for availability at the time. For all the good things about elastic on-demand scalability, this one will continue to be a downside until security services are available that can detect and reject attacks at the “edge” of the cloud provider’s environment.

Second, you could terminate SSL connections on a capable Load balancer or application delivery controller. Most modern solutions of this ilk will recognize the malformed hello and refuse to accept them. This is not much different than the server responding with an error except that offloading the task of dealing with SSL and the miscreant traffic means the server can still respond easily to legitimate requests. If you have some other component terminating SSL, check if it’s capable of recognizing the malformed headers. If not, and you have a network-side scripting capable component downstream from it, you can always use the third option to intercept the requests, inspect them, and instruct the component to reject it if it contains malformed data.
Think SSL DoS Not Dangerous?

Back in the days when I was still putting products to the test I often evaluated SSL-terminating solutions like appliances and specialized hardware on PCI cards. To test capacity we basically created the equivalent of a DoS attack.

In one test we generated enough load to fry the PCI slot on a Sun Sparc server. Fried electronics is not a pleasant smell, especially in a confined space. In another test, a now long defunct product would continually reboot itself when load reached a specific point, effectively disrupting service completely for all servers behind it.

Many SSL-terminating solutions require licensing for a specific TPS rate, and a DoS can easily surpass that rate. When SSL is handled by the servers themselves, the additional strain from processing high amounts of SSL can effectively reduce the ability of the server to handle other legitimate requests to zero, consuming all available resources in a relatively short period of time. Even if an SSL DoS won’t fry your circuitry, it can certainly be a Bad Thing for your applications and infrastructure and cause performance degradations and, if you’re in ‘the cloud’, possibly additional charges.

The third option is to put into place a filter or network-side script that examines the request and determines whether it is legitimate or not.

The fourth option is to put in place IDS/IPS (such as Snort) filters to handle the requests.

So you’ve got options, you just need to decide which one will best serve your needs. I, of course, heavily recommend any option that detects and rejects as close to the perimeter as possible so as to avoid needless resource consumption, but more important than that is simply stopping the attack.

Read the original blog entry...

More Stories By Lori MacVittie

Lori MacVittie is responsible for education and evangelism of application services available across F5’s entire product suite. Her role includes authorship of technical materials and participation in a number of community-based forums and industry standards organizations, among other efforts. MacVittie has extensive programming experience as an application architect, as well as network and systems development and administration expertise. Prior to joining F5, MacVittie was an award-winning Senior Technology Editor at Network Computing Magazine, where she conducted product research and evaluation focused on integration with application and network architectures, and authored articles on a variety of topics aimed at IT professionals. Her most recent area of focus included SOA-related products and architectures. She holds a B.S. in Information and Computing Science from the University of Wisconsin at Green Bay, and an M.S. in Computer Science from Nova Southeastern University.

IoT & Smart Cities Stories
Cloud-enabled transformation has evolved from cost saving measure to business innovation strategy -- one that combines the cloud with cognitive capabilities to drive market disruption. Learn how you can achieve the insight and agility you need to gain a competitive advantage. Industry-acclaimed CTO and cloud expert, Shankar Kalyana presents. Only the most exceptional IBMers are appointed with the rare distinction of IBM Fellow, the highest technical honor in the company. Shankar has also receive...
Nicolas Fierro is CEO of MIMIR Blockchain Solutions. He is a programmer, technologist, and operations dev who has worked with Ethereum and blockchain since 2014. His knowledge in blockchain dates to when he performed dev ops services to the Ethereum Foundation as one the privileged few developers to work with the original core team in Switzerland.
In his general session at 19th Cloud Expo, Manish Dixit, VP of Product and Engineering at Dice, discussed how Dice leverages data insights and tools to help both tech professionals and recruiters better understand how skills relate to each other and which skills are in high demand using interactive visualizations and salary indicator tools to maximize earning potential. Manish Dixit is VP of Product and Engineering at Dice. As the leader of the Product, Engineering and Data Sciences team at D...
Dynatrace is an application performance management software company with products for the information technology departments and digital business owners of medium and large businesses. Building the Future of Monitoring with Artificial Intelligence. Today we can collect lots and lots of performance data. We build beautiful dashboards and even have fancy query languages to access and transform the data. Still performance data is a secret language only a couple of people understand. The more busine...
Bill Schmarzo, author of "Big Data: Understanding How Data Powers Big Business" and "Big Data MBA: Driving Business Strategies with Data Science," is responsible for setting the strategy and defining the Big Data service offerings and capabilities for EMC Global Services Big Data Practice. As the CTO for the Big Data Practice, he is responsible for working with organizations to help them identify where and how to start their big data journeys. He's written several white papers, is an avid blogge...
René Bostic is the Technical VP of the IBM Cloud Unit in North America. Enjoying her career with IBM during the modern millennial technological era, she is an expert in cloud computing, DevOps and emerging cloud technologies such as Blockchain. Her strengths and core competencies include a proven record of accomplishments in consensus building at all levels to assess, plan, and implement enterprise and cloud computing solutions. René is a member of the Society of Women Engineers (SWE) and a m...
Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settlement products to hedge funds and investment banks. After, he co-founded a revenue cycle management company where he learned about Bitcoin and eventually Ethereal. Andrew's role at ConsenSys Enterprise is a mul...
Whenever a new technology hits the high points of hype, everyone starts talking about it like it will solve all their business problems. Blockchain is one of those technologies. According to Gartner's latest report on the hype cycle of emerging technologies, blockchain has just passed the peak of their hype cycle curve. If you read the news articles about it, one would think it has taken over the technology world. No disruptive technology is without its challenges and potential impediments t...
If a machine can invent, does this mean the end of the patent system as we know it? The patent system, both in the US and Europe, allows companies to protect their inventions and helps foster innovation. However, Artificial Intelligence (AI) could be set to disrupt the patent system as we know it. This talk will examine how AI may change the patent landscape in the years to come. Furthermore, ways in which companies can best protect their AI related inventions will be examined from both a US and...
Bill Schmarzo, Tech Chair of "Big Data | Analytics" of upcoming CloudEXPO | DXWorldEXPO New York (November 12-13, 2018, New York City) today announced the outline and schedule of the track. "The track has been designed in experience/degree order," said Schmarzo. "So, that folks who attend the entire track can leave the conference with some of the skills necessary to get their work done when they get back to their offices. It actually ties back to some work that I'm doing at the University of San...