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Peter Coogan | November 4th, 2009
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The Fragus exploit pack showed up on our radar a few months ago and has been steadily growing to become one of the most prevalent exploit packs being seen in the wild today by Symantec. It is similar to other popular exploit packs available—such as Unique, YES, Eleonore, and Liberty—but it brings some new and interesting features with it. Exploit packages are generally designed as a means to allow attackers to group and serve exploits from their website against the browsers of unsuspecting visitors. It is done in a nice GUI form, hosted on a Web server, and allows the attacker to generally choose which exploits to run. Once exploited, a final payload is served to the system. All of this is dished up in a control panel with some nice statistics on how successful the campaign has been.  

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Ben Nahorney | November 3rd, 2009
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Threats targeting the Macintosh platform are much less common than those targeting Windows. The same can be said about video games, where Windows is the dominate platform of the two. Combining games and malware has happened before, but a Mac game performing malicious activities? That’s something relatively new.

Takashi Katsuki, one of our Tokyo engineers, came across just that today. The game looks to be a throw-back to the classic Space Invaders/Galaga style of games from the early 1980s. However, what brings this game into the realm of malicious code is that for every alien ship you destroy, the game deletes a file from your home directory.

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Andrea Lelli | October 31st, 2009
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Sure we have heard a lot about bots and botnets. One key component of a botnet is the command-and-control (C&C) server, which as we know can come in several flavours (IRC, Web pages, newsgroups, custom servers, etc.). Yet, here comes Trojan.Whitewell, which, being tired of old C&C channels, decides to pick up Facebook as a coordinator for the C&C server. I use the word “coordinator” because the Trojan only receives some configuration data from its Facebook account—the actual command execution and data reporting is done through a third party Web server.

The Trojan was sent through a popular malware distribution channel that is also related to other prevalent threats such as Trojan.Bredolab. The distribution technique is pretty simple: they send documents (PDF, or MS Office formats) containing exploits for known vulnerabilities. These documents usually...

Shunichi Imano | October 29th, 2009
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Symantec Security Response has become aware of a Trojan Horse we detect as Trojan.Ramvicrype. The Trojan uses the RC4 algorithm to encrypt files on compromised computers, rendering them unusable. Presence of files with a .vicrypt extension is a sure-fire sign of infection.

Trojan.Ramvicrype is a little different from most other Ransomware programs we’ve seen in the past. Typically these kinds of threats display a message prompting users to visit a certain Web page or email a specific address. Users will end up paying the online criminals in exchange for keys that can be used to unlock the computer or decrypt the encrypted files.

Previously posted blogs on the subject of Ransomware can be found at:

Eric Chien | October 28th, 2009
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A Blackberry application called PhoneSnoop was released recently, which resulted in an advisory from US-CERT. The application allows remote users to listen in on a Blackberry user’s surroundings.   
 
snoop1.png

The application as seen when installed on a Blackberry

The application is actually quite straightforward and uses standard Blackberry APIs that allow the interception of incoming phone calls. When a call is received from a preconfigured phone number, the call is automatically answered and the speakerphone is engaged. Someone who has had this application installed may not notice the incoming phone call and not realize someone can now listen in on the immediate surroundings.

We’d consider this application just a proof of concept for a variety of reasons, including the author himself...

Nicolas Falliere | October 20th, 2009
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This chapter in our Clampi saga brings us back to the malware’s logging facility. As we saw before, one of Clampi’s modules, codenamed LOGGER, is responsible for logging outgoing information going to a determined list of URLs – stored in a data file as CRCs.

One problem arises with banking sites that preprocess the user’s personal information before sending it over HTTPS—it’s done using client-side JavaScript.  For instance, a hash of the input PIN number could be sent instead of the PIN number itself. This mechanism adds an extra layer of security, preventing malware from sniffing network traffic at one end of the SSL tunnel. But still, it’s only covering one end. It’s more secure than no encryption, but still not great. At least two methods exist to get around this:

  • Setting up a keylogger using either software (...
Nicolas Falliere | October 16th, 2009
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Let’s continue our Trojan.Clampi blog series by discussing three more modules downloaded and executed by Clampi. These modules share the common goal of gathering information, private or not, contained on the compromised computer. They don’t intercept network traffic like the Logger module does (described in my previous blog).

The PROT module
This module gathers private information from several sources, including Protected Storage (PStore), which contains user credentials stored by Internet Explorer or Outlook for instance. Interestingly, it also sets specific registry values in order to facilitate the creation of new entries in the PStore.
For instance, it sets the following registry entires:

  • HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\ “...
Gilou Tenebro | October 14th, 2009
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Trojan.Bredolab is a threat that has been distributed widely and consistently this year. This research paper takes a closer look at the Trojan to discover how it works, why it’s so widespread, and the motivations behind it.

In short, Bredolab is distributed by spam emails and drive-by-download attacks. (In fact, last month we blogged about a wave of spam emails used to distribute it.) Once it’s on a computer, Bredolab downloads and installs a variety of other threats. This process is outlined in the following diagram.
 
bredo_attacks_BN.jpg

We have seen Bredolab downloading password stealers, bots, rootkits, backdoors,...

Symantec Security Response | October 13th, 2009
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Malware authors often leave hidden messages in files for analysts to find or for other malware authors to see. However, finding a curse on my whole family in a flash exploit file came as somewhat of a surprise!

The file in question was being distributed on the Internet circa June of this year and was being hosted on some Chinese domains. After decompressing the file and extracting the ActionScript I saw some Chinese characters used within the script. I don’t speak Chinese myself, so I had one of our engineers who does translate the message:

Warning.jpg
 
This roughly translates to:

“Dadong declares that: This file is used only for internal technical research, if you decrypt it your whole family will die, if you use it as a part of a Trojan your whole family will die also! If you use this file illegally you take...

Nicolas Falliere | October 12th, 2009
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As mentioned in our previous blog entry, most of the Trojan.Clampi features reside in separate modules that are sent by a remote server in response to clients’ queries. In this part of this blog series, we’ll have a look at one of the modules used by the malware to steal login credentials mostly from banking Web sites.
 
This module is codenamed LOGGER by the threat. After decryption, the beginning of the module’s raw data looks like this (compressed):

blog-2-image-1.jpg

To avoid downloading the module each time Clampi runs, it is stored in the registry (in an encrypted form) in a value named “Mxx”, where “xx” is a zero-based number...

Peter Coogan | October 7th, 2009
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We thought it might be interesting to provide some additional information on the Butterfly bot kit, following our blog published last week entitled The Mariposa Butterfly. We posted that blog in response to a report that half of the Fortune 100 companies have been compromised by a botnet dubbed Mariposa (Spanish for "butterfly"). The Butterfly bot kit's creator, known as Iserdo, markets the following features of the bot kit in the user manual supplied with the kit (the below snippet is taken directly from the user manual):

a) Features of bot base

1. Polymorphic code and strings
    code related to bot functionality is encoded
    everytime with different key, same goes for
    strings
2. Installation into hidden location
    installs into location where it is impossible
    to access with windows explorer...
Nicolas Falliere | October 6th, 2009
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Trojan.Clampi is one of the hottest malware around, and as such, received a fair amount of media coverage, as well as technical reports describing some of its functionalities. As part of our ongoing blog series, we will be discussing interesting and rarely presented aspects of Clampi. Today, we’ll introduce an important aspect of Clampi: the network communication.

First of all, if you’re not familiar with this malware already, Clampi is a Trojan horse whose main purpose is to steal private information: user passwords, login credentials, software licenses, credit card numbers, bank account information, etc. Note that Clampi’s operations are performed by helper modules, downloaded by the main executable, and stored in the Windows registry.

Once the threat is installed on a computer, it connects to one of the gateway servers listed in the registry value “GatesList...

John McDonald | October 1st, 2009
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There has been a flurry of news articles over the past few days on what the media appears to have labeled the Mariposa botnet, after the name a Canadian information security firm used for this particular threat. The ‘butterfly’ in the title of this article refers to the fact that the threat is believed to stem from the Butterfly bot kit, which is no longer for sale.

Several security vendors have commented that this threat isn't new, and indeed Symantec has been detecting variants of it since as early as January this year. We currently have various detection names for these samples, the majority of which are one variant or another of W32.SillyFDC, Trojan Horse or more recently Packed.Generic...

Piotr Krysiuk | September 30th, 2009
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It is not very common for a file infector to do more than simply introduce trivial modifications to the files it infects. Virus authors usually avoid complex modifications to the files because of the possibility of corruption. W32.Xpaj.B is one of exceptions.

W32.Xpaj.B is an entry-point obscuring, polymorphic file infector. The virus is not completely new and shares some of its characteristics with its predecessor, W32.Xpaj, first seen in June 2008. What sets this creature apart is the amount of effort its authors have invested into hiding their malicious code in the files it infects.

W32.XPaj.B is more sophisticated than your average file infector. To make finding its malicious code difficult, the virus avoids putting any obvious signs in the infected files. Unlike most simple viruses, it doesn’t attempt to execute the virus code by hijacking control when the infected file is started. Instead, the virus overwrites some subroutines from the infected files with...

Patrick Fitzgerald | September 25th, 2009
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It’s well known that malware is growing more sophisticated, but few threats have had us scratching our heads like Trojan.Clampi. In order to remove the mystery around this threat, Security Response will be publishing a series of blogs talking about various aspects of Clampi. As an introduction, we’d like to present a brief overview of the threat.

Distribution
Trojan.Clampi has been around for a number of years now. During this time it has gone through many iterations, changing its code with a view to avoid detection and also to make it difficult for researchers to analyze.

From our analysis it seems that Clampi has mainly affected machines in the US. Clampi infection rates seem to be skewed towards countries where English is the primary language.  This may indicate the first infections were as a result of malicious drive-by attacks on...