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Phish… it’s what’s for dinner

I’ve been watching the latest phishing attack happening on Twitter for the last week or so. It seems to be one major campaign that keeps changing the DM (direct message) text every couple of hours. It’s been messages like

“woah… you’re on this ”
“LOL..Nice look ”
“This thing has your pic ”

The links got to videos.twitter. and videos.blog.. Sophos customers using the WS1000 are safe as we’ve been blocking the domain. Interestingly, we’re now seeing new URL shorteners being used, such as wapurl.co.uk and others. Seems the malware authors are tired of bit.ly and 3.ly blocking their stuff or perhaps because third party applications such as TweetDeck won’t preview those, but will happily open them.

I had someone ask the question “Why phish for Twitter credentials?” We saw this type of attack on Facebook. Lots of phishing messages, links, and posts were posted to capture credentials. Then later on we saw the malware attachments spammed out to the email addresses associated with the compromised accounts and when the malware was run, it became part of a botnet to send yet more spam. Taking this history, we are wondering if this will take a similar turn and start sending out malicious emails purporting to be from Twitter saying “Update your account/password” or “Updated Terms of Service, please open.”

Another reason for the phishing attacks would be to expand the “attack surface”. More and more people are tweeting from their iPhones, Androids, Blackberries, Palms and other smart phones. This means a whole new vector to be exploited, since again, most third party Twitter apps do not preview the shortened URL.

We have to say it again, PLEASE be careful out there. Just because a message came from a friend/follower doesn’t mean it’s completely trustworthy. Check the link with an expander service such as LongURL, use NoScript and URL expander plugins and keep your security software and OS up to date. Otherwise, your machine is likely to be “dinner”

Posted on November 10th, 2009 by Beth Jones, SophosLabs US
Filed under: General, Spam, Web

                                         

Fedor Fans Beware

For those of you who aren’t mixed martial arts fans, this past Saturday night was the Strikeforce television event where one of the worlds greatest fighters Fedor Emelianenko fought Brett Rogers, and what a fight it was. It was a fairly significant fight since Fedor is generally not seen fighting in North America and his exposure is fairly limited, but it aired on regular cable TV on CBS so you can be sure plenty of people saw it. As the fights were being televised at one point the gym that each fighter trained at was shown on the screen and I didn’t give it a second thought until this afternoon.

While doing my daily rounds of digging through newly infected pages I spotted something in a link that looked familiar, Red Devil Sports Club, the gym Fedor trains at. The infected page was being hosted on a website used to help promote MMA gyms, and sure enough when you Google the terms “Red Devil Sports Club” the website in question appears on the first page of results. Following the link led to a page that had been compromised with the latest Gumblar variation which Fraser blogged about yesterday.

It seems recent celebrity deaths aren’t the only thing hackers abuse to find new victims. Granted, the method of delivery is a little more obscure since not everyone is going to go and Google the name of the gym Fedor trains at that they heard while watching TV, but it’s just one of many methods this kind of malware uses to spread.

Posted on November 10th, 2009 by Onur Komili, Researcher, SophosLabs, Canada
Filed under: General, Web

                                         

Gumblar revisited

Readers may have noticed some of the recent rumours about new Gumblar-related activity (see for example here or here). The original Gumblar attack (May 2009) involved the mass-defacement of huge numbers of legitimate sites with a malicious script Sophos products blocked as Troj/JSRedir-R. The purpose of this was to infect users with a data-stealing Trojan known as Troj/Daonol-Fam.

The payload of the recent attacks looks similar, the malicious binaries now being detected as Mal/Daonol-A.

As with the previous wave of site defacements, it appears to be stolen FTP credentials that is driving the new attacks. These enable the attackers to upload malicious PHP scripts which can then be used to construct the attack. Contrary to the previous attacks, the payload is now also being hosted on compromised hosts, making the attacks more resilient.

At the end of last week, we managed to get hold of one of the key PHP script components being used by the attackers. Analysis of the script gives us some interesting insights into these attacks.

The PHP script can be used by the attackers to inject a malicious script into all suitable pages on the victim site. Files below ~200kB whose extension do not match any of the following are targeted (up to a maximum of 5 within any particular directory):

• .zip
• .rar
• .gz
• .jpg
• .gif
• .avi
• .mp3
• .wma
• .mpg
• .png
• .txt
• .swf
• .css
• .js
• .log
• .pdf
• .ppt
• .fla
• .as
• .tar

Some simple techniques are used to make the injected scripts mildly polymorphic (between each injected page). These include function/variable substitution and simple string obfuscation.

The purpose of the injected script is simple - adding a script element to the page which will cause the browser to load further malicious content from a remote server (hosted on another compromised site).

The PHP script makes it trivial for the attackers to change the redirection payload of the scripts that are injected into pages. Issuing a HTTP request to the PHP script with the desired target domain in the query string is all that is required. So, requesting http://compromised_site_A/path/gumblar.php?dom=compromised_site_B will result in:

• removal of any injected scripts previously added to suitable pages on compromised_site_A
• injection of new scripts, whose payload will be to load content from compromised_site_B

This makes the new wave of attacks more resilient to URL filtering. Sophos customers are protected - aside from detecting the payload as Mal/Daonol-A, pages injected with the redirection scripts are blocked as Troj/JSRedir-AE. Indications at this point are that a large volume of sites have been affected - the detection is already contributing to almost 4% of all web-based threats for the past 48 hours.

Additionally, detection for the malicious PHP scripts uploaded to compromised sites has been added as Troj/PHPMod-B. If you are a webmaster or hosting provider and encounter this detection, please let us know. It would be interesting to collect further samples of the PHP kits being used.

Posted on November 8th, 2009 by Fraser Howard, SophosLabs UK
Filed under: General, Malware, Web

                                         

Fake Facebook e-mail “Subject: updated account agreement”

It has been a busy week so far for the writers of e-mail exploits and this Friday morning they continue to try to trick the public into installing their malware. The latest threat to fall into the Sophos spam traps purports to come from Facebook and requests the user to update their account agreement by unzipping and executing an attached file called agreement.exe.

Dear Facebook user,

Due to Facebook policy changes, all Facebook users must submit a new, updated account agreement, regardless of their original account start date.
Accounts that do not submit the updated account agreement by the deadline will have restricted.

Please unzip the attached file and run “agreement.exe” by double-clicking it.

Thanks,
The Facebook Team

Of course we all know that it is pure folly to unzip and run an unknown executable attached to an e-mail, however the implied threat of finding their access to Facebook restricted by ‘the deadline’, whenever that may be, is obviously severe enough to panic a number of the users of Facebook into falling for this trick.  

They really should think twice, by agreeing to install agreement.exe they will install a Trojan.

Sophos detects this threat as Troj/Dloadr-CWS.

Posted on November 6th, 2009 by Julie Yeates, SophosLabs UK
Filed under: Malware, Spam

                                         

How a phish works

Recently we have received a PayPal phishing email and it looks like this.

 

It is not hard to spot that this email is a phish since clicking on the link does not take us to PayPal.com but to some remote site (which is already blocked by Sophos’s web appliance).

The web page loaded from this site disguises itself as PayPal.com as shown below.

 

However, this web page is just an image of the real PayPal.com web page. All the tabs and links on this fake web page can not be selected and only the email address and password text field can be used. This is another obvious sign that the web site is fake. By logging in with some fake  email address and password we were lead to the following page.

 

By clicking on the link we were directed to another web page as shown below.

How can we tell that this web page is fake? It is quite simple, this page has the following URL.

We  provided some fake  account and address information, the site then redirects  us to a page asking us to supply our banking details.

We then decided to supply more fake banking information to the web page and see where it will lead us. As a result we were lead to the following page.

 

Finally, the site will refresh and redirect us to the genuine PayPal.com web page.

 

Posted on November 6th, 2009 by Victor
Filed under: General

                                         

Is it art? Controversy over OSX/LoseGame-A

Last week, SophosLabs released detection for OSX/LoseGame-A and following Symantec’s publishing detection (which they call OSX.Loosemaque) there has been some controversy about whether this is a game or malware (see 1, 2, 3).

From my point of view this is malware. Why?

1. The warning screen isn’t  multi-lingual if English isn’t your first language you will still recognize ‘PRESS ANY KEY TO CONTINUE’.
2. Even if English is your first language a child looking for games on the computer will not read the warning but press through to the game.



3. Would our corporate customers want this on their networks?

The concept behind OSX/LoseGame-A is ill conceived and it is likely to have malicious consequences not considered by the author.

Posted on November 5th, 2009 by Pob, SophosLabs, UK
Filed under: Macintosh, Malware

                                         

You have won a lottery!!!

Malware coming in the form of attachments is not unusual these days.

However, malware can also be found in links provided within e-mails:

According to its name,  “You have won!.pdf”, it suggests to people that they have won some kind of a lottery.  However,  the URLs lead you to a malicious file, which seems to have been taken down (access to which is already blocked by Sophos’s web appliance).

So, please beware of such malicious links and their fake claims that you have won some money ;-).

If you are curious of what you did win, you can always click on the link and win yourself a piece of malware ;-).

Posted on November 5th, 2009 by Liang Zhang, SophosLabs AU
Filed under: General

                                         

From Server/Outlook update to FDIC to facebook phish: now with a twist

In the past few weeks, the authors behind Zbot has been busy. Around October 12 we have seen the server upgrade spam with links. Later on the 14th we’ve seen the same campaign with the malware attached to similar-looking server upgrade notices. By the 22nd of October, the spam messages touts Outlook updates.

For a few days during the past week, the group has turned their attention to the Federal Deposit Insurance Corporation (FDIC), spamming out links to malware sites with the message below:

With the global economy as it is, notice of bank failures would certainly draw a lot of attention and irrational behavior. After all, thoughts of hard-earned money being gone forever is going to scare a lot of people. Of course, downloading the “personal FDIC insurance file” would give nothing but grief. The bank deposits are still safe, but the computer would probably get infected.

After the blast of FDIC messages, the Zbot authors turned to facebook as their latest platform to spread malware. However, they added a twist to it. The messages are well-crafted to look like a real Facebook message:

The message asks the user to update their facebook account. The new twist is that, when they get to the linked site, there is no link to download an executable yet. Instead, they’re shown with a fake Facebook login page:

Victims who have entered their facebook login would get their account details phished, probably for the purpose of spreading more malware. Since this is not a real facebook page, any random login info would bring you to this next page:

It is on this page where the malware author provides an executable for download. This file, updatetool.exe is a Zbot executable that is proactive detected as Mal/EncPk-LE.

With the creative social engineering that the Zbot authors have been using, users should be real careful when reading messages, whether it’s in an email or from a social network. Avoid clicking links directly, manually type the address to access the site, and not executing files would do a lot in protecting one’s computer.

Posted on November 4th, 2009 by SavioL, SophosLabs, Canada
Filed under: Exploits, General, Malware, Spam, Uncategorized, Vulnerabilities

                                         

Mal/Iframe-N: Another winning infection?

Back in May, we posted some stats on the prevalence of Troj/JSRedir-R. Last week, I asked was Mal/Iframe-N: The next big threat?. Looking through our stats on malware hosted on websites this morning I saw that Mal/Iframe-N fifth in the overall stats for October.

Looking at the latter part of the month from the 21st (when the detection was published) onwards.

Mal/Iframe-N is clearly first and if the results are extrapolated for the whole month Mal/Iframe-N should have easily beat Mal/Iframe-F into second place!

Late last week, I downloaded:

• 2819 infected URIs infected with Mal/Iframe-N
• hosted on 2294 different domains
• with 163 different TLDs including:

.edu.in
.edu.tr
.edu.tw
.edu.ua
.ej.am
.eng.br
.es
.eu
.fi
.fr
.fr.cr
.ge
.go.th
.gov.br
.gov.pk
.gov.tr
.gr

I have had a few correspondences with other security researchers regarding this threat (see iframes are EVIL! Hate Zeus!) particularly with Unmask Parasites who has gone into more details of this type of threat (see 1, 2) who like me originally thought that the ‘onload’ attribute wasn’t legal in an iframe. Two things changed my mind:

1. Visiting an infected site on a goat machine.
2. The number of infected sites (>40, 000).

In someways the second fact is more persuasive as malware authors don’t tend do things for no reason.

Posted on November 2nd, 2009 by Pob, SophosLabs, UK
Filed under: General, Malware, Web

                                         

There’s Malware on Elm Street this Halloween … with pumpkins!

 

It appears that this Halloween the malware writers preferred choice of infection vector is by using SEO (Search Engine Optimization) techniques to poison popular search terms.

We at SophosLabs have seen relatively few email campaigns that exploit Halloween this year, but there have been plenty of campaigns pushing malware loaded URL’s into festive search terms.

We have various Fake AV families featuring highly:

and

Which leads to the familiar:

and

There are also families that pose as fake media codecs exploiting Halloween to push their wares:

As users wise up to the dangers of email attachments we are seeing SEO poisoning becoming a more and more popular attack vector.

Sophos detects this years nightmares variously as Mal/FakeAvJs-A, Mal/Krap-A and Mal/EncPk-LH.

Posted on October 31st, 2009 by James Wyke, SophosLabs UK
Filed under: General, Malware