South Korean banks and broadcasters took phish bait in cyberattack

More details of the cyberattack on multiple banks and media companies in South Korea on Wednesday have emerged, suggesting that at least part of the attack was launched through a phishing campaign against employees of the companies. According to a report from Trend Micro's security lab, the "wiper" malware that struck at least six different companies was delivered disguised as a document in an e-mail.

The attachment was first noticed by e-mail scanners on March 18, the day before the attack was triggered. The e-mail was purportedly from a bank; Trend Micro's Deep Discovery threat scanning software recognized the message as coming from a host that had been used to distribute malware in the past.

The attachment, disguised as a document, was actually the installer for the "wiper" malware. It also carried PuTTY SSH and SCP clients, and a bash script designed to be used in an attack against Unix servers that the target machines had connection profiles for. When activated, the dropper attempted to create SSH sessions to Unix hosts with root privileges and erase key directories, as Ars reported yesterday.

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Apple follows Google, Facebook, and others with two-step authentication

Apple has finally responded to increasing online security threats by introducing two-step authentication for iCloud. Like Google and other companies that already employ two-step authentication, Apple's system would provide an extra layer of security on top of the existing iCloud passwords when users try to access their accounts from unrecognized devices. iCloud users can set up two-step authentication on Apple IDs today by going to the Apple ID website and clicking the "Password and Security" tab.

Apple walks you through the process on its Apple ID management site.

For Apple, this means an authentication code is either sent via SMS to a phone number or found within the Find My iPhone app (if you have it installed) whenever you try to log in from somewhere new. This means that a potential attacker will have a harder time getting into your iCloud account without having physical access to your "trusted" device receiving the code. (Users are prompted to set up at least one trusted device when they turn on two-step authentication, though you can have more than one if you like.) Currently, two-step authentication is available to iCloud users in the US, UK, Australia, Ireland, and New Zealand.

One of the benefits to setting this up on your iCloud account is that you'll no longer have to rely on security questions—which are inherently insecure—in order to gain access to your account if you lose your password. The downside (if you consider it that) is that once you set up two-step authentication, Apple will no longer be able to reset your password for you should you lose or forget it. This is what ended up biting Wired editor Mat Honan in the behind when his various accounts were compromised—hackers were able to gather enough personal information from Honan's e-mail and Amazon accounts to trick Apple support into resetting his iCloud password, giving them free reign to remotely wipe his iPhone, iPad, and MacBook.

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How whitehats stopped the DDoS attack that knocked Spamhaus offline

Unlike Unicast-based networks, Anycast systems use dozens of individual data centers to dilute the effects of distributed denial-of-service attacks.

As an international organization that disrupts spam operators, the Spamhaus Project has made its share of enemies. Many of those enemies possess the Internet equivalent of millions of water cannons that can be turned on in an instant to flood targets with more traffic than they can possibly stand.

On Tuesday, Spamhaus came under a torrential deluge—75 gigabits of junk data every second—making it impossible for anyone to access the group's website (the real-time blacklists that ISPs use to filter billions of spam messages were never effected). Spamhaus quickly turned to CloudFlare, a company that secures websites and helps mitigate the effects of distributed denial-of-service attacks.

This is a story about how the attackers were able to flood a single site with so much traffic, and the way CloudFlare blocked it using a routing methodology known as Anycast.

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VSkimmer Botnet Targets Credit Card Payment Terminals

April 2

This blog has been updated with McAfee’s NSP detection. See end of blog.

While monitoring a Russian underground forum recently, we came across a discussion about a Trojan for sale that can steal credit card information from machines running Windows for financial transactions and credit card payments. The malware, vSkimmer, can detect the card readers, grab all the information from the Windows machines attached to these readers, and send that data to a control server. The author of the thread also discusses other capabilities of this malware, which appears to be a successor of Dexter, but with additional functions.

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We already know about botnets such as Zeus and SpyEye, which perform financial fraud using extremely sophisticated techniques including  intercepting the victims’ banking transactions. VSkimmer  is another example of how financial fraud is actively evolving and how financial Trojans are developed and passed around in the underground community. This botnet is particularly interesting because it directly targets card-payment terminals running Windows.

Our Automated Botnet Replication Framework first saw this Trojan on January 18. We’ve analyzed  samples of this malware and figured out how it steals the credit card information and its additional control functionalities. While performing the API tracing , we found it uses fairly standard antidebugging techniques:

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The malware collects the following information from the infected machine and sends it to the control server:

  • Machine GUID from the Registry
  • Locale info
  • Username
  • Hostname
  • OS version

 

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This malware uses a standard installation mechanism and copies itself as svchost.exe into %APPDATA% , modifies the registry key to add itself under the authorized list of apps, and runs ShellExecute to launch the process. One function of vSkimmer if the Internet is not available is to wait for a USB device with the volume name KARTOXA007  to be connected to the infected machine and to copy all the logs with the file name dumz.log and the card info collected from the victim to the USB drive.

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I checked by disconnecting from the Internet: The malware enumerated all the drives and created the file dumz.log in the drive with the preceding name.

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Extracting credit card information

VSkimmer maintains the whitelisted process, which it skips while enumerating the running processes on the infected machine.

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Once vSkimmer finds any running process not in the whitelist, it runs OpenProcess and ReadProcessMemory to read the memory pages of the process and invokes the pattern-matching algorithm to match the regular expression “?[3-9]{1}[0-9]{12,19}[D=\\u0061][0-9]{10,30}\\??”)” and extract the card info read by the payment devices. This is done recursively for every process running in the infected machine and not on the whitelist.

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VSkimmer control

Before communicating with the control server, the malware B64-encodes all the machine information collected and appends it to the URI. The encoded string follow this format:

  • machine guid|build_id|bot_version|Windows_version|Host_name|User_Name

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Next, vSkimmer creates the HTTP request and connects to the control server:

 

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While this malware ran, we saw the following response. Note that the commands are within the <cmd> </cmd> tag.

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Once vSkimmer receives a response from the server, it executes the following routine to parse the command:

 

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Because the response from the server during execution was <cmd>null</cmd>, the malware extracts the 3-byte command and tries to match it with the other commands implemented by vSkimmer. First it checks if the command from the server is “dlx.”

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If not, then vSkimmer checks for the “upd” command. These commands implement the HTTP download and execute (“dlx”) and update of the bot (“upd”), respectively.

As we saw earlier in this post, vSkimmer can also grab the Track 2 data stored on the magnetic strip of the credit cards. This track stores all the card information including the card number. (You can read more about the Track 2 data format on Wikipedia. The chief information:

  • Primary Account Number: the number printed on the front of the card
  • Expiration Date
  • Service Code: the three-digit number

 

VSkimmer bot control panel

Here’s a look at the control panel of the command server:

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UPDATE

McAfee NSP detection:

Attack ID: 0x4880a600
Attack Name: BOT: VSkimmer Traffic Detected
Sigset: Intrushield Network Security Signature Set 7.5.34.10