Posts Tagged 'Malware'

October 23, 2012

Tips from the Abuse Department: Know Spam. Stop Spam.

As an abuse administrator, I'm surrounded by spam on a daily basis. When someone sends an abuse-related complaint to our abuse@softlayer.com contact address, it gets added to our ticket queue, and our Abuse SLayers take time to investigate and follow up with the customers whose servers violate our acceptable use policy. The majority of those abuse-related submissions are reporting spam coming from our network, and in my interaction with customers, I've noticed that spam (and the source of spam) is widely misunderstood.

Most spam tickets we create on customer accounts pinpoint spam sent from a compromised or exploited server. Our direct customer didn't send the phishing email, malware distribution, pharmacy advertisement or pornographic spam, but that activity came from their account. While they're accountable for the abusive behavior coming from their server, in many cases, they don't know that there's a problem until we post an abuse ticket on their account. These servers are targeted and compromised by common techniques and exploits that could have been easily avoided, but they aren't very well known outside the world of abuse.

To protect yourself from a spammer, you need to think like a spammer. You need to understand how someone might try to exploit your environment so that you can prevent them from doing so. As you're looking at ways to secure your server proactively, make sure you target these five exploits in particular:

1. User Auth Login

This is by far the most common exploit to used to send spam. This method involves a person or script using the credentials of a user to send spam through a domain's mail server. The majority of these incidences are caused by malware on a client PC that obtains the login and password for a domain user and uses that information to log on and send mail from the client PC through the server. Often, these spam messages are sent through a botnet command structure.

When an account is compromised, simply changing the password for the compromised user on the server usually won't stop the abuse. We see quite a few accounts that continue to send spam after an initial abuse ticket results in a password change. Most servers that are sending spam with this method are found to only be sending a small amount of spam at any given time to avoid detection. The low volume of spam that is being sent per server is made up for by the fact that there are thousands of servers being used for the same spamming campaigns.

In order to stop the User Auth Login exploit, a customer needs to clean all of the malicious software (malware) from their environments. To prevent future User Auth Login compromises, users should be made aware of the potential dangers of untrusted software, and if they believe their machines are infected, they need to know what to do.

2. Tell-a-friend Exploitation

The User Auth Login technique is the most common method employed by spammers, but the "tell-a-friend" script exploitation isn't far behind when it comes to volume of affected servers. This spamming method find websites that use scripts to invite users to refer friends to a page or product. Spammers will use the 'Your Message' field in one of these scripts to input their own content and links, and they'll push the actual page referral link to the bottom of the message. When these site scripts aren't secure, the spammer will use them to send hundreds or thousands of messages.

To avoid having your website fall victim to this type of spam, be very wary of any widget or script you add. If you need to add Facebook, Twitter and email "share" functionality to your site, make sure you incorporate a tell-a-friend script that does not allow for customizable messages or does not accept input of more than one email address. Also, users won't need the "cc" or "bcc" fields, so you can be sure those are axed as well. If you can't find a good "share" script that you're comfortable with from a security perspective, it might be a good idea to remove that functionality to avoid exploitation.

3. Uploaded Mailers

Spam sent via an uploaded third party mailer can sometimes prove difficult for admins to locate. An uploaded third party mailer could be capable of creating it's own outbound SMTP connection, and that would allow a program to bypass the existing MTA on the server and render any legitimate mail logs useless for investigation. Another challenge is that a php mailer can be uploaded to a location within a user's web content, and that mailer is run by the user 'nobody' (the default Apache user).

We strongly suggest configuring your server to have the mail headers show the script's user (that's not the Apache default user) and the location the script is running from on the server. Many times, these kinds of mailers are maliciously uploaded after a user's FTP password is been compromised, so be sure your FTP login information is secure.

4. Software Exploits

The "software exploits" category casts a huge shadow. Every piece of software on a server — from mail servers, content management systems and control panels to the operating system itself — can be targeted by hackers. They probe servers to find security vulnerabilities and weak coding, and when they find a vulnerability, they take control.

The hacker who found the software vulnerability might not actually take advantage of the exploit immediately. That user may sell access to other entities for their use, and that use often ends up being spam. In addition to having strong firewall rules and access restrictions, you should update and maintain the current stable versions of all software on your servers.

5. WordPress Exploits

WordPress exploits would technically fall under the "Software Exploits" category, but I'm breaking it out into its own category simply due to the volume of spam issues that are the result of exploiting this particular piece of software. The first step to protecting against spam being sent through this source is to make sure you have the latest version of WordPress installed. With that done, be sure to research the latest security plugins for that version and install any that are applicable to your environment.

These five techniques are not the only ones used by spammers to take advantage of your environment, but they are some of the most common. To protect yourself from becoming a source of spam, make your servers a more difficult target to exploit. To stop spam, you need to know spam. Now that you know spam, it's time to stop it. Ask questions, test your environment regularly and watch your logs for any unexplained usage.

-Andrew

December 6, 2010

I, the undersigned, certify under penalty of perjury...

“I, the undersigned, certify under penalty of perjury”, “We believe the following host has recently been compromised”, “I received the below unsolicited commercial e-mail”, are a few statements that we as The Softlayer Abuse Department receive on a routine basis. The responsibility of responding to these quite serious matters in of itself is what gives us our motivation and niche in the overall scheme of this company: the protection of our networks global reputation. Without a firm and diligent abuse department, many of our customers would experience extreme packet loss left and right. Some customers may be affected by another provider’s block on an entire subnet, due to a single server periodically attacking their network for a month. Others would assuredly have their IP addresses consistently listed in spam databases, and therefore restricting e-mail contact to most or all of their clients. So in order to help keep these things from happening; we need to ensure that any reported or detected abusive activities occurring on our network are thoroughly responded to. We do this by analyzing abuse reports, determining the nature of the issues, and if an issue is valid, a ticket is opened with the customer for further correspondence as we track the issues resolution. At the same time, we maintain communication with other organizations and providers to ensure that matters are quickly addressed.

While most issues are resolved, or are being resolved within 24 to 72 hours, some issues require a quicker response. One of these is Phishing sites, which need to be removed within a shorter time frame. Our procedures regarding these sites are due to the fact that they are one of the most dangerous and wide spread issues on the internet today. If you’re not familiar with, or just want to read up on some of the latest news regarding these sites, you can get everything you need to know at APWG’s (Anti-Phishing Working Group) website. Softlayer’s membership within APWG allows us access to the most recent industry level trends and activities for a range of abusive issues. This gives us a much greater insight and oversight to identify and resolve issues that are negatively affecting our network. I can’t speak too much publicly past the above general time frames; since most abuse work is to some degree like spam filters, immediate disclosure of detection methods and procedures would render them useless. However, I can say that we believe one of the most effective methods for combating phishing is consumer education. If users are familiar with how fraudulent operations work, they are more likely to recognize components of them when they see them and not become victims. In support of this concept, we encourage all of our customers to respond to phishing site ’take downs’ by replacing the phishing site with a redirect to the APWG’s phishing education landing page. This page is an informative document that explains to the user that they were about to become a victim of illegal activity, and goes on to explain phishing in more detail. Most people in today’s modern society won’t go too far out of their way to obtain new information regarding trends in cybercrime. As such, the moment in which someone is about to be the victim of a phishing scam is considered to the ‘teachable moment’. This is the moment that someone has clicked on a link that they believe goes to their banks’ website, but are redirected to an educational page about phishing instead. The page is also configured to work with a variety of different languages, based on the client browser settings. As more people encounter the APWG’s landing page instead of a phishing site, the faster phishing education will spread and the less number of potential victims will exist. You may find information on how to implement the redirect here.

One of the next most concerning matters that we address is, servers being used by unauthorized third parties to conduct some form of outbound attack. While each are in there own way malicious and need the same attention, here’s a few specifics on some of the general different types. Password Cracking/Brute Force – this is typically done by malicious content attacking multiple hosts simultaneously while attempting various username and password combinations, typically with a massive list of pre-defined words. One of the easiest ways to help protect a server against being effected is to change at least your SSH, FTP, RDP, to non standard ports and ensure that you have complex passwords. I would also advise enabling account lockouts after a certain number of failed login attempts. Another predominant type of malicious scanning is doing so on an entire netblock by checking each host within them to see if one or more ports are open per host, which is then reported back to a database for later use in the latter form of attack. Essentially anything that is in some way part of an intrusion attempt is a priority.

Next we move on to an area of abuse that has most likely affected all of us at some point in time – Malware. This is a very general term we use to describe any software that has been written with malicious intent. The possible functions and uses for malware are only limited by the imagination and the software platforms that they are built upon, assuming that the infection process doesn’t accidentally crash the server. Various forms of malware have been identified as responsible for every type of abuse issue noted in this article at some point in time. While at the same time, malware on your server is not the guaranteed reason it may be conducting outbound abusive activities. Most specific malware related tickets are in reference to a single or series of malicious files that are publicly accessible. These issues are often resolved quickly upon deletion of the file(s) in question. However, it is also equally as important to ensure that any security vulnerabilities that allowed these files to be uploaded are repaired, or you can almost guarantee that the problem will reoccur. Microsoft reported that during the 1st half of 2008, over 90% of system vulnerability and subsequent infections were attributable to ‘weak’ applications rather than malware targeting the operating system itself. – Microsoft S.I.R. Vulnerabilities within the application layer remained the predominant risk throughout the 2nd half of 2008 as well. Malware in general has remained a formidable electronic adversary through 2009 and on to the present. As such, it is very important to ensure that you are using the most current version of all installed applications, and that they were written by a trusted source in addition to the maintaining the operating system security.

One very common form of malware effecting servers is an IRC(Internet Relay Chat) bot. One bot alone can be responsible for the infections of countless other machines. This is commonly done by injecting malicious code into poorly written PHP scripts. However, the bigger problem with an IRC bot is the fact that it’s connected to an IRC Botnet Controller, which is capable of commanding massive amounts of infected hosts simultaneously. While these are typically used for spam or other similar illicit activities, there is still the potential for the infected servers to be involved with even worse situations. These are in effect: A virtual army that’s literally capable of taking small countries off of the internet grid. In June of 2007, the F.B.I. initiated operation ‘Bot Roast’ an ongoing investigation to locate the people behind the wires. But in the mean time, needless to say, these matters need to be addressed as soon as possible.

During our triaging of abuse reports, we also address the very common issue of Spam. The three major types listed in order of priority are: Phishing, General Fraudulence, and other infected hosts Spam. However, you may also be audited, if you will, with a Spam ticket regarding a mailing list one of your clients is operating. For additional information regarding email marketing and the industry’s best practices, spamhaus.org's FAQ is a very useful resource.

Keeping the above in mind, there is also one last thing to consider; maintain a backup of all removed malicious content after it has been found. This evidence could prove invaluable to law enforcement, should the request for it be presented. We also encourage you to review your access logs to determine the source IP address(s) of any intruder or other malicious entity, such that you may report it to the appropriate organization. As it is with many other aspects of life, communication regarding these issues remains critical for timely and appropriate resolutions.

-Andrew Smith - Martinez

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May 21, 2009

Anti-Spyware Workshop

I just got back from participating in a panel discussion at the most recent Anti-Spyware Coalition Public Workshop. The title of the panel session was “Who Owns the Problem”. You can see who all of the participants were, but it was a good session with representation from the FBI, Symantec, Paypal, the Center for Democracy and Technology, Stopbadware.org and KnujOn.

A lot of the session was focused on end user security regarding spyware, rogue anti-virus, malware and other general badware. But part of the discussion was in regards to the security efforts of the hosting industry in general and SoftLayer specifically. Some of the things we deal with in the hosting industry are second nature to those of us that have been here for a while. But when you start talking about it in front of a different crowd, you begin to appreciate the different perspectives that are out there.

For instance, one common perception (held by some, but obviously not by all) is that once we are made aware of a server that has malware on it, all we have to do is pull the plug on the server and the problem is resolved. However, sometimes the consequences of doing so are high enough to be worthy of a second look. For instance, consider the scenario where SoftLayer rents a server to a customer. That customer slices the server into virtuals using Parallel’s Virtuozzo product and rents a virtual to another customer. That customer puts Cpanel on it to sell shared hosting accounts. Now SoftLayer is 2 layers removed from the actual end user. If that end user’s website gets compromised and begins to distribute malware, how do we at SoftLayer deal with the problem. Ideally, we tell our customer and they tell their customer and they tell the end user about the problem. The end user reacts quickly and cleans up the site. That’s not anywhere close to “best case scenario”, but I would call that a reasonable real-world response.

The problem is, if any of the individuals in that chain of communication fails to react quickly, then the response time for that issue is drastically impacted and more people are potentially victimized by the malware. At what point do we pull the plug on the server? At what point do we decide that all of the other customers on the server have to suffer because of the one bad apple or because of a slow response time from one customers in the chain of communication? Websense did a study that showed in the second half of 2007, over half of all sites distributing malware were themselves compromised sites so the scenario described above is actually a very common problem. It also highlights that there is one more victim in the incident; the web site owner.

We tend to deal with each case as prudently and expeditiously as possible in every abuse report that we receive. In some cases, we pull the plug immediately. In others, we try very hard to work with the customer to resolve the issue. But in all cases, we are constantly working to act as quickly as possible on each individual case.

This is just one of the many scenarios that we have to deal with and it highlights why having a good relationship with your provider is such an important factor when choosing someone to help supply or service your IT needs.

-SamF

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