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Archive for the 'botnet' Category

No Ifs or Bots: if only…


Monday, November 30th, 2009

I came across a nice article today by Dennis Fisher on “The Root of the Botnet Epidemic”.

It's the start of what looks like an interesting series on "the roots, growth and effects of the botnet epidemic" and the first aricle takes a historical overview of the situation around the turn of the century, looking at the first DDoS attacks, Mafiaboy, trinoo, stachedraht and all that, and the beginning of "botmaster-friendly" features like Windows interfaces with point-and-click option selection and some telling quotes  from Joe Stewart and Jose Nazario.

We seem to have come a long way since those primitive Linux tools and the introduction of techniques like rate-limiting to shield the backbone from malicious packet storms, but not so far as to encourage complacency.

If you're interested in the historical aspect, here are a couple of references off my bookshelf that you might find of interest:

"Chapter 4: Big Bad Botnets" in the "AVIEN Malware Defense Guide" (ed. Harley, Syngress 2007)

"Botnets: the Killer Web App" (ed. Schiller & Binkley, Syngress 2007)

Plus: "Net of the Living Dead: Bots, Botnets and Zombies" (Harley, Lee; 2008) at http://www.eset.com/download/whitepapers/Net_Living_Dead.pdf

David Harley BA CISSP FBCS CITP
Director of Malware Intelligence

Also blogging at:
http://blog.isc2.org/
http://avien.net/blog
http://blogs.securiteam.com
http://dharley.wordpress.com/

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IBot revisited (briefly)


Monday, November 23rd, 2009

I don't want to flog (or blog) this iPhone bot thing to death: after all, the number of potential victims should be shrinking all the time. However, having updated my previous blog (http://www.eset.com/threat-center/blog/2009/11/22/ibot-mark-2-go-straight-to-jail-do-not-pass-go)  on the topic a couple of times, I thought I'd actually go to a new blog rather than insert update 3.

So here are the update bits again.

[Update, courtesy of Mikko: this worm targets at least one Dutch bank, and activates when users go to the online bank with an infected iPhone ]

[Update 2, courtesy of Paul Ducklin: how to change the password of an infected phone. I could just tell you what the password is, but you might want to read the whole blog.http://bit.ly/4JJMCu

And the latest update, courtesy of Henk Diemer, comes from http://www.security.nl/artikel/31552/1/iPhone_botnet_raakt_controle_kwijt.html, which broke a lot of the previous news on this and related malware. (Sorry, it's in Dutch.) The article indicates that the botnet has "lost control".

This may not be as positive as it sounds. It may just mean that the C&C server has been taken down through ISP or law enforcement action, which would be nice. On the other hand, it may mean that the server has been switched or some other change in the botnet  infrastructure made. C&C switching is standard botnet practice, and could have been accelerated because of attention from the media and the security industry.

Every time we publicise something like this, we have to weigh the immediate benefit to potential and actual victims against the fact that we may make the situation worse, for instance by stampeding the bad guys into moving the goalposts . Sadly, there's no handy cost/benefit analysis tool to make the choice for us.

Perhaps the least attractive possibility is that another group of bad guys has stuck its oar in, though I've seen no evidence of that being the case, so far. If it did happen, that would suggest another rite of passage completed, and a step beyond mere "Proof of Concept" testing.

David Harley BA CISSP FBCS CITP
Director of Malware Intelligence

Also blogging at:
http://blog.isc2.org/
http://avien.net/blog
http://blogs.securiteam.com
http://dharley.wordpress.com/

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iBot Mark 2: Go Straight To Jail Do Not Pass Go


Sunday, November 22nd, 2009

[Update, courtesy of Mikko: this worm targets at least one Dutch bank, and activates when users go to the online bank with an infected iPhone ]

[Update 2, courtesy of Paul Ducklin: how to change the password of an infected phone. I could just tell you what the password is, but you might want to read the whole blog.http://bit.ly/4JJMCu]

Back in April, I blogged about an article in that month's Virus Bulletin by  Mario Ballano Barcena and Alfredo Pesoli about the first serious attempt to creat a Mac botnet. The issue containin that article, by the way, is now available on the Virus Bulletin web site at  http://www.virusbtn.com/pdf/magazine/2009/200904.pdf: you have to register with the web site to access it, but registration is free.

Rather more recently, I've blogged several times on threats aimed at users of jailbroken iphones: the latest was posted at http://www.eset.com/threat-center/blog/2009/11/13/when-is-a-worm-not-a-worm. And now there's a worrying convergence.

Over the weekend, I've been seeing reports from several sources of further malware that potentially affects users in the Netherlands, Hungary, Portugal, Brazil and elsewhere. Chester Wisniewski's blog indicates that a wider spread of ISPs is targeted than previously (UPC in the Netherlands and T-Mobile, as well as Optus in Australia, which has already been targeted several times, and unnamed Hungarian and Portuguese providers), and that jailbroken iPod Touch devices are also vulnerable.

The new worm doesn't seem to be particularly .widespread, which isn't surprising, given that the subset of vulnerable device owners should already have shrunken significantly, with jailbroken device users either restoring Apple firmware through iTunes, ie "unjailbreaking", or at least changing the default passwords. (By "vulnerable" we mean iPhones that are not only jailbroken, have SSH installed, and haven't changed passwords.) However, http://www.security.nl/artikel/31542 does suggest a lot of activity on the T-Mobile network.

What is both interesting and disquieting, though, is that it has botnet functionality: if it's able to infect, it connects to Command and Control (C&C) box in Lithuania with the current IP address 92.61.38.16 (that can change!) to upload data and receive instructions from the C&C server. It also changes the default password, so if you find yourself in possession of a compromised device, your best bet is to restore the firmware. In addition, it seems to be looking for banking authentication data (mTANs – see http://en.wikipedia.org/wiki/Transaction_authentication_number).

Irrespective of widespread the threat really is, it should be taken seriously. This has gone way beyond pranks with rickrolling and wallpaper, and even incidental damage such as the draining of an infected device's battery due to network activity. The scope of this particular vulnerability is limited, but by no means exhausted: there is already a lot of source code out there that can be adapted for further threats. However, the recent and rapid escalation from pranks to worm to hacker tool to bot is an indicator of serious attention from fraudsters and other criminals. Neither Apple nor its fans can afford to be complacent about the supposed superiority of Apple products in terms of safety and security: Big Brother's criminal counterpart is out there scanning for vulnerabilties.

What we're seeing now is less the unarguable difference between safe and unsafe platforms, than a difference in volume. And that merits serious attention.

Hat tip to Chester Wisniewski and Mikko Hypponen for making available some of the information here.

David Harley BA CISSP FBCS CITP
Director of Malware Intelligence

Also blogging at:
http://blog.isc2.org/
http://avien.net/blog
http://blogs.securiteam.com
http://dharley.wordpress.com/

Botnets, Complacency and the UK Government


Monday, November 16th, 2009

Gadi Evron drew my attention in an article for Dark Reading to a piece in IT Pro by Asavin Wattanajantra. The piece quotes Dr. Steve Marsh, of the UK's Cabinet Office (the Office of Cyber Security, to be precise) as saying that botnet operators are interested in money-generating attacks on the private sector, not causing damage to "national networks".

You might recall that I made a not dissimilar point in this blog with regard to Conficker, when we were all wondering what April 1st would bring: basically, I maintained that the Conficker gang was unlikely to attack the Internet infrastructure, as some journalists and others were fearing.

However, I don't feel, for a number of reasons, that the UK government (or any government) should be complacent about the risk from botnet-directed attacks for purposes of espionage or cyberwarfare (whatever you may understand by that particularl buzzword). I've explained my reasons for that in a blog for (ISC)2 ( International Information Systems Security Certification Consortium) at http://blog.isc2.org/isc2_blog/2009/11/botnets-not-a-problem.html.

David Harley BA CISSP FBCS CITP
Director of Malware Intelligence

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You’ve Got Bot!!!


Tuesday, October 20th, 2009

 

Comcast has announced that they are trialing a new service that alerts users when their computers are infected. You can read about it here: http://news.cnet.com/8301-27080_3-10370996-245.html. Essentially what happens is that when Comcast notices traffic that looks like bot related traffic they will pop up a message on the subscriber’s computer that indicates there is a problem and suggests steps to help clean up the computer.

I believe this is an exploratory step toward what we call the “walled garden”. In the “walled garden” scenario a user’s computer is not allowed out on the internet until they have cleaned up the infection. The walled garden approach is perhaps somewhat draconian, but does have merit. The problem is that false positives will be exceptionally annoying and troublesome for consumers and ISPs alike. The pop-up notice approach will allow Comcast to fine tune the detection mechanisms.

I applaud Comcast for this trial, but I wish Comcast took user account security seriously. What do I mean? If you use POP3 with a Comcast email account the way they have you set up your account means that your username and password are transmitted in plain text. This is an egregious security problem and it is hard to believe that Comcast might get their pop ups right when they appear to be so callous about user account credentials.

In the security community we are expecting to see the bad guys start spoofing ISP virus warnings if the practice becomes widespread enough. The measure of how significant the problem becomes will be the count of computer cleaned up by the notification verses the number of users social engineered but the notifications.

For the time being, Comcast is on the right path, but appears to lack the security awareness to pull this maneuver of properly.

Randy Abrams
Director of Technical Education

September’s Global Threat Report


Tuesday, October 6th, 2009

ESET released its Global Threat Report for the month of September, 2009, identifying the top ten threats seen during the month by ESET’s ThreatSense.Net™ cloud.  You can view the report here and, as always, the complete collection is available here in the Threat Trends section of our web site.  While the report identifies a number of different types of malware, in this article, I’d like to focus on the Conficker worm as well as the class of worms which spread via AutoRun.

Conficker

While the overall percentage of reports is on the decline, the Conficker worm (also known as Win32/Conficker, Downadup and Kido) continues to make its presence known throughout cyberspace, accounting for 10.75% of detections.  This was actually a slightly upswing from August’s 10.12%, but given that many businesses have employees on vacation during the summer, is not unexpected, and still below the 12.58% seen in July.  The Win32/Conficker worm spreads using several vectors, such as unpatched operating systems, vulnerable network shares and via AutoRun on removable media such as USB flash drives.  ESET detects the malicious AUTORUN.INF file used by the worm to spread separately from its Win32 portable executable file, and currently sees a ratio of about one AUTORUN.INF file to every 4.8 executable file detections of the worm.
 
While a substantial number of Conficker infestations are blocked at the removable media infection layer, there are still a large number of networks outs there where the worm is spreading.  While ESET’s software does detect and remove the Conficker worm, it is important to keep in mind that anti-malware is only one component of security, and that other steps need to be taken as well in order to keep a network clean:
  • If you have not already done so, deploy Microsoft’s MS08-067 patch for the vulnerability initially used by the worm to infect systems.  It is also a good idea to install the MS08-068 and MS09-001 patches as well.
  • Disable AutoRun on removable media.  More about this below.
  • Use strong passwords.  The Conficker worm contains a set of commonly-used passwords in order to make it easier for the worm to spread across network shares.  A list is mentioned in this news article.  For more information about choosing good passwords, see these three earlier ThreatBlog articles here, here and here.  We also have a white paper on the subject.
ESET classifies Conficker into several variants, depending upon their behavior and technology.  For more information on each classification, see the following ESET Virus Encyclopedia entries: Conficker.A, Conficker.AA, Conficker.AE, Conficker.AQ, Conficker.AR and Conficker.X.

Worms continue to spread quick as a flash

The AUTORUN.INF file, a technology originally envisioned a decade-and-a-half ago to simplify the deployment of content on CD-ROMs, continues to be a top vector for malware.  ESET uses a variety of heuristic algorithms and generic signatures to detect both the AUTORUN.INF files which contain links to malware—detected as INF/Autorun and coming in at third place with 7.53% detections—as well as the malware which creates them: Win32/Autorun, coming in at ninth place with 0.78%.  Together, they account for 8.31% of detections seen in September, but it is important to keep in mind that other threats which spread via AUTORUN.INF files are first identified as specific threats such as Conficker, so the actual number of threats seen which make use of this technique is higher.
 
In order to block malware which spreads in this fashion, the option to use AutoRun on removable media needs to be disabled.  This has been discussed earlier in ESET’s Threat blog here and here and US CERT, a federal agency responsible for securing the government’s computers give instructions here, as well.
Microsoft’s forthcoming versions of Windows, Windows 7 for desktops and Windows Server 2008 R2 for servers will implement this, and the change has been made available for older versions of Microsoft Windows, such as Windows XP, Vista, Server 2003 and Server 2008.  For more information, including tools to apply the change, see this knowledgebase article on Microsoft’s web site.
 
As mentioned previously, anti-malware software is only part of the security equation.  Removing this un-needed functionality from your PC instantly immunizes it against a technique used by nearly a fifth of malware out there.  The tools and techniques used to disable AutoRun functionality can be applied in under a minute on a single PC and are easily scriptable so they can be employed in a managed computer environment with a minimum amount of effort.  We strongly recommend doing this.

Conclusion

As you can see, malware relies on a number of ways to spread, some of which are solved by updating the operating system and others by changing the less-secure behavior that was chosen in less secure times to more modern secure settings.
 
We’ll discuss the threats we saw last month in further detail, as well as explain how to better defend yourself in a future blog article.
 
Regards,

Aryeh Goretsky MVP, ZCSE
Distinguished Researcher

Can’t Surf the Web?


Friday, September 18th, 2009

Australia’s Internet Industry Association (IIA) is working on best practices for isolating computers with bots on them (http://iia.net.au/index.php/initiatives/isps-guide.html)
At the same time, the Internet Engineering Task Force (IETF) is also drafting a document about the same thing (http://tools.ietf.org/html/draft-oreirdan-mody-bot-remediation-03)

If these recommendations are adopted then people who have bots on their computers would have to get their computers cleaned up before their ISP would allow them to surf the web. The idea has been around for quite a while, however issues such as cost and privacy have been the main barriers to the plans.

I do think it is likely that eventually your ISP will adopt an approach to identify customers who have bots on their computers and then limit their web access to a site that can help them clean their computer. I think it will be a few years before any major ISPs actually have full implementation of quarantining infected users, but the day may come that you won’t be able to surf the web if your computer is infected.

Randy Abrams
Director of Technical Education

Is Apple’s Snow Leopard Immune to Malware?


Tuesday, September 8th, 2009

There is an interesting and humorous work of fiction at http://www.appleinsider.com/articles/09/09/07/inside_mac_os_x_snow_leopard_malware_protection.html. Humorous as long as you don’t believe it!

The article starts out saying “Safari, like other modern browsers, already flags certain websites that are known to be used to distribute malicious software”. That’s a nice layer of defense, but there are sites many sites that have been compromised and distribute malware, as well as new sites cropping up all of the time.

The article says that “there is no real malware problem on the Mac, in part because it’s hard to write viral code that infects Mac OS X and very easy for Apple to roll out a patch that closes any discovered holes.”

To start with, the security community is seeing an increase in attacks against Mac users. Recently a Mac botnet was discovered (http://arstechnica.com/apple/news/2009/04/evidence-suggests-first-zombie-mac-botnet-is-active.ars). Apple would not have added any malware protection to Snow Leopard, their newest operating system, if it wasn’t a problem.

Most malware is not viral. So, the claim about it being hard to write viral code is pretty irrelevant. Speaking of viral code, the very first worm that significantly disrupted the internet ran on UNIX systems. Snow Leopard is a flavor of UNIX. It has long been known that viruses and worms can be written for UNIX operating systems. It isn’t hard to write viruses for a Mac, it is the configuration of the operating system that makes them hard to spread. Even with a properly configured operating UNIX based operating system a worm can spread, especially if the system isn’t patched. Not only does the system need to be patched, but the third party applications must be patched as well, or you can have serious problems on a Mac.

That Apple can patch holes quickly is highly theoretical as they are often criticized for being slow to roll out patches.

Completely naively the author claims that Mac bugs aren’t valuable. Apple computers often contain personal information which is valuable for identity theft. Apple computers often contain business information that is of value. Apple computers can be used in botnets, which makes them valuable.

The author claims that Windows isn’t as easy to update. Windows updates itself automatically if you let it.

The author continues to harp on viruses when viruses are much less than 10% of the malware which affects users.

The comparison of an iPhone to a Mac is rather ludicrous. The iPhone has a much less general purpose operating system than a Mac has. The conclusion is not supported by the premise.

The author claims that viruses that bombard Windows have never affected Mac users, when in fact, Office Macro viruses often ran just fine on Macs and infected other files on the Mac.
The comparison of Snow Leopard’s blacklist to the iPhone White list is apples and oranges. A whitelist is proactive where a blacklist is reactive. The premise that snow Leopard’s built-in blacklist makes building Mac malware less attractive to thugs is simply ludicrous. It is trivial for a thug to defeat the blacklist.

The author is correct that there is much less malware targeting the Mac, but not correct in stating that there are no real world problems, as we have seen with the recently discovered Mac botnet. In fact, this is not the first Mac botnet (http://voices.washingtonpost.com/securityfix/2009/04/worlds_first_mac_botnet_hardly.html)

So, while currently there are few attacks against Macs, we are seeing an increase in attention to Macs by the bad guys. Mac users may be able to get by now without antivirus software, just as most PC users were able to prior to about 1995, but I would expect that to be changing in the next couple of years.

Randy Abrams
Director of Technical Education

A Motivation for the Twitter Attack?


Friday, August 7th, 2009

Some people are speculating that the motivation for the Twitter attack was to try to silence one person. There are really good signs that the attack against an individual was what took down Twitter, but still we really don’t know. I speculated that it might be a show of force to try to sell botnet resources. It still could be that. If you’re going to demonstrate your weapon you still need a sample target. In this case it may have been killing two birds with one stone. Of course, this also is conjecture. We may never know the true motivation for the attack. Still, I have to believe that there are some criminal who were pretty upset at the loss of revenue when they were unable to attack the users of Twitter.

Randy Abrams
Director of Technical Education

Cyber war or Cyber hype?


Friday, July 10th, 2009

Cyber war or Cyber hype?

On July 4th several US government web sites were hit with a distributed denial of service (DDOS) attack. In human speak that means you couldn’t get to those web sites because too many other computers were making them unavailable. Many of the attack failed, but some sites, like www.ftc.gov effectively disappeared. Shortly after this attack another wave of attacks started and also included sites in South Korea.

Some reports blamed North Korea for the attack. It does appear than many of the attacking computers were from South Korea, but it is difficult to know who really is behind the attack. The computers actually dong the attacking are infected with programs called “bots”. These computers belong to ordinary people, but are zombies under the control of someone else. Maybe it was North Korea behind the attack, but that doesn’t make a lot of sense to me or most security experts.

The fact that it is unlikely to be North Korea is not enough to prevent rampant hype. One or two people speculate that it is North Korea and not only does North Korea get blamed, but a media whore in the US congress calls for a cyber attack against North Korea, regardless of whether or not they are to blame. Here’s the story. Http://www.wired.com/threatlevel/2009/07/show-of-force/

To see Rep. Peter Hoekstra’s enlightened speech, click here.

The attacks are only a cyber war in the minds of the deranged, the manipulative, and the ignorant. Frankly, those blaming North Korea for this round of attacks are far more likely suspects than North Korea.  Rep Heokstra has far more to gain from attacking these sites and blaming North Korea than North Korea had to gain from instigating the attacks.

This looks like a classic Wag the Dog.

Randy Abrams
Director of Technical Education