Thursday, April 24, 2008

Crimeware in the Middle - Zeus

Virtual greed, or response rate optimization? The idea of converging phishing emails with embedded exploits and banking malware is nothing new, in fact phishers realizing that combining attack approaches can increase the chance of achieving their objective which in this case is either logging the authentication process or hijacking it, often forget that the phishing email could have succeeded without the embedded malware or exploit, which in many cases would have triggered an alarm.

Yesterday, Uriel Maimon posted an overview of the convergence of Rock Phish emails with Zeus, a crimeware kit used to deliver banking trojans :

"The Trojan that was used in this attack belonged to the "Zeus" family of malware. Zeus is a nefarious type of Trojan for multiple reasons:

1. The Zeus Trojan is a kit for sale: Anyone in the criminal community can purchase it for roughly $700. This means that the Rock group did not need to develop new skill-sets to write Trojan horses; they just purchased it on the open market. In the past 6 months RSA's Anti-Fraud Command Center has detected more than 150 different uses of the Zeus kit, each one infecting on average roughly 4,000 different computers a day.

2. Resistance to detection: The kit purchased is a binary generator. Each use creates a new binary file, and these files are radically different from each other -- making them notoriously difficult for anti-virus or security software to detect. To date very few variants have had effective anti-virus signatures against them and each use of the kit usually makes existing signatures ineffective. Just like in most cases, this particular use of the Zeus kit did not have any a
nti-virus detection (with the popular engines we tested) at the time of this writing.

3. Rich feature set: the Zeus Trojan has many startling capabilities. In addition to listening in on the submission of forms in the browser, the Trojan also has advanced capabilities, for instance the ability to take screenshots of a victim's machine, or control it remotely, or add additional pages to a website and monitor it, or steal passwords that have been stored by popular programs (remember when you clicked on the "Remember this password?" checkbox?)... And the features-list goes on.
As I look upon this blissful union of fraud and crime technologies, I can only envy the criminals who can find such coupling. Looking forward to my next birthday, I can only hope that I will have the opportunity to find such partnership in my own life (and maybe give my mother one less reason for disappointment)."

We cannot talk about Zeus unless we compare it to another such crimeware kit serving banking trojans, in this the Metaphisher kit. Metaphisher is particularly interested because of its much more customized GUI, it's modular nature, allowing its sellers to lower or increase the price depending on which modules you'd like included, and which ones you'd like excluded, where a module means a preconfigured fakes, TANs, and phishing pages for all the banks in a country of choice. Moreover, despite that both, Zeus and Metaphisher are open source, and therefore malicious parties visionary enough to build communities around their kits in order to enjoy the innovation brought by multiple parties, Metaphisher has a bigger community next to Zeus, considered as the MPack in the web malware exploitations kits, namely a bit of an outdated commodity that is of course still capable of doing what does best - hijacking E-banking sessions and logging them to the level of impersonation.

How are the authors of Zeus describing the kit themselves? Here's a description :

"ZeuS has the following main features and properties (full list is given here, in your part of assembling this list may not):

- Written in VC + + 8.0, without the use of RTL, etc., on pure WinAPI, this is achieved at the expense of small size (10-25 Kb, depends on the assembly).

- There has its own process, through this can not be detected in the process list.

- Workaround most firewall (including the popular Outpost Firewall versions 3, 4, but suschetvuet temporary small problem with antishpionom). Not a guarantee unimpeded reception incoming connections.

- Difficult to d
etect finder / analysis, bot sets the victim and creates a file, the system files and arbitrary size.
- Works in limited accounts Windows (work in the guest account is not currently supported).
- Nevid ekvaristiki for antivirus, Bot body is encrypted.

- Some way creates a suspected its presence, if you do not want it. Here is the view of the fact that many authors do love spyware: unloading firewall, antivirus, the ban on their renewal, blocking Ctrl + Alt + Del, etc.

- Locking Windows Firewall (the feature is required only for the smooth reception incoming connections).
- All your settings / logs / team keeps bot / Takes / sends encrypted on HTTP (S) protocol. (ie, in text form data will see only you, everything else bot <-> server will look like garbage).

- Detecting NAT through verification of their IP through your preferred site.

- A separate configuration file that allows itself to protect against loss in cases of inaccessibility botneta main server. Plus additional (reserve) configuration files, to which the bot will ap
ply, will not be available when the main configuration file. This system ensures the survival of your botneta in 90% of cases.
- Ability to work with any browsers / programs work through wininet.dll (Internet Explorer, AOL, Maxton, etc.):

- Intercepting POST-data + interception hitting (including inserted data from the clipboard).

- Transparent URL-redirection (at feyk sites, etc.) c task redirect the simplest terms (for example: only when GET or POST request, in the presence or absence of certain data in POST-request).

- Transparent HTTP (S) substitution content (Web inzhekt, which allows a substitute for not only HTML pages, but also any other type of data). Substitution of sets with the help of guidance masks substitute.

- Obtaining the required contents page, with the exception HTML-tags. Based on Web inzhekte.
- Custo
mizable TAN-grabber for any country.
- Obtaining a list of questions and answers in the bank "Bank Of America" after successful authentication.

- Removing POST-needed data on the right URL.

- Ideal Virtual Keylogger solution: After a call to the requested URL, a screenshot happening in the area, where was clicking.

- Receiving certificates from the repository "MY" (certificates marked "No exports" are not exported correctly) and its clearance. Following is any imported certificate will be saved on the server.

- Intercepting ID / password protocols POP3 and FTP in the independence of the port and its record in the log only with a successful authorise.

- Changing the local DNS, removal / appendix records in the file% system32% \ drivers \ etc \ hosts, ie comparison specified domain with the IP for WinSocket.

- Keeps c
ontents Protected Storage at first start the computer.
- Removes S ookies from the cache when Internet Explorer first run on a computer.

- Search on the logical disk files by mask or download a specific file.

- Recorded just visited the page at first start the computer. Useful when installing through sployty, if you buy a download service from the suspect, you can see that even loaded in parallel.
- Getting screenshot with the victim's computer in real time, the computer must be located outside the NAT.
- Admission commands from the server and sending reports back on the successful implementation. (There are currently launching a local / remote file an immediate update the configuration file, the destruction OS).

- Socks4-server.

- HTTP (S) PROXY-server.
- Bot Upgrading to the latest version (URL new version set in the configuration file).

What's most important to keep in mind in regarding to these crimeware kits, is that the sellers are shifting from product-centered to service-centered propositions, and while an year ago they would have been selling the kit only, today they've realized that it's the output of the kit in terms of logged stolen accounting data that they're selling. Committing identity theft and abusing stolen E-banking accounting data is already a service, compared to the product it used to be.

Related posts:
Targeted Spamming of Bankers Malware
Localized Bankers Malware Campaign
Client Application for Secure E-banking?
Defeating Virtual Keyboards
PayPal's Security Key
Nuclear Grabber Kit
Apophis Kit