Security

Most people may think they're smart enough not to answer an obvious spam message. But is that really the case?

Almost one third of consumers questioned admitted answering e-mails they suspected were spam, says a survey released Wednesday by the Messaging Anti-Abuse Working Group (MAAWG).

Among those who responded to spam, 17 percent said they clicked on it by mistake, 13 percent said they sent a note to the spammer to complain, while 12 percent said they were interested in the product or service.

Why do people respond to spam?

(Credit: Messaging Anti-Abuse Working Group)

The MAAWG's survey study, "A Look at Consumers' Awareness of Email Security and Practices," also discovered that about two-thirds of the people considered themselves "very" or "somewhat" knowledgeable about Internet security. Most of them use antivirus software, but 21 percent said they take no action to prevent spam or dangerous e-mail from hitting their in-box.

(Credit: Messaging Anti-Abuse Working Group )

Further, the survey found that 80 percent of users questioned doubted their computers were ever at risk of being infected with a "bot" that can send spam and create other problems without the user knowing it.

"Spamming has morphed from an isolated hacker playing with some code into a well-developed underground economy that feeds off reputable users' machines to avoid detection," says MAAWG Chair Michael O'Reirdan. "Consumers shouldn't be afraid to use e-mail, but they need to be computer smart and learn how to avoid these problems."

The study was based on phone and online interviews conducted in December and January with 800 computer users in the U.S. and Canada who said they were not "security experts" and who used e-mail addresses not managed by an IT department.

The Messaging Anti-Abuse Working Group is a global organization comprising ISPs, network operators, and other tech companies. The group's goal is to reduce the abuse and threats affecting electronic mail by focusing on technology, industry collaboration, and public policy initiatives.

Arbor Networks found that DDoS attack size (in gigabits) nearly doubled in 2008 from the previous year.

(Credit: Arbor Networks)

Internet service providers now spend most of their IT security resources detecting and mitigating distributed denial-of-service attacks, concludes a report from Arbor Networks.

The fourth edition of the Worldwide Infrastructure Security Report, released Tuesday, was based on how 70 lead security engineers responded to 90 questions. As in the previous three reports, ISPs reported attacks where their networks were overloaded with packets, what's called a distributed denial-of-service (DDoS) attack. However, this year, the ISPs indicated the attacks were not only larger in size but that most of them were stretching the upper limits of their security resources in order to deal with such attacks.

Rob Malan, founder and chief technology officer of Arbor Networks, said the DDoS attacks seen this year broke the 40-gigabit barrier, nearly double the volume of last year's attacks. He warned that if next year's attacks again double in size, "most carriers will be unable to deal with those attacks."

In assessing the attacks, Arbor Networks found "brute force," a catch-all term, was the dominant method used. The security firm looked at traditional means of DDoS--syn flood, udp flood--as well as anything else that artificially created network congestion. Malan told CNET News that despite the massive size, the attacks themselves demonstrated "little sophistication" and were simply "trying to overwhelm network bandwidth."

One consequence of this method was that upstream providers of the targets were increasingly being affected. "If an attacker takes out capacity of (the upstream) routers you're (also) starving the target," he said. Malan said attackers were also using reflective attacks, which use different pieces of DNS structure to redirect traffic away from a target.

While flood-based attacks represented 42 percent of the attacks reported, followed by protocol exhaustion-based at 24 percent, Arbor Networks also saw a sharp increase this year in application-based attacks, which accounted for 17 percent of the attacks.

Malan explained that with application-based attacks, bot-infected computers worldwide make connections to a targeted site, then "use an application protocol to deliver a perfectly valid request, not a vulnerability, not something that an IDS or other type of firewall would necessarily flag." For example, a botnet might instruct its zombie computers worldwide to do a back-end query off a database. "By itself it's not bad, but if you have multiple such requests, then you tie up the application--in this case database--resources on the back end," he said.

The report does contain some good news. Arbor Networks found detection and mitigation of these attacks to be increasing as well. Fifteen percent of the respondents said, on average, they can mitigate an attack within 10 minutes of detection. However, 30 percent said mitigation still takes them over an hour.

But finding the criminals responsible for these attacks is not a high priority. Arbor Networks found that ISPs have little time to involve law enforcement. "It's hard on carriers," said Malan. "They get paid on traffic, not to do forensic analysis. So it's hard from their perspective to make the economics work."

(Credit: Arbor Networks)

In February of 2005, a Miami man sued Bank of America for not adequately protecting him against a $90,000 fraudulent wire transfer to the Parex Bank in Latvia. Joe Lopez was the first online user to sue his financial institution for not protecting his assets from a computer hacker.

Lopez, owner of a computer and copier supply business, accused Bank of America of negligence and breach of contract for not alerting him in advance to the existence of a piece of malware known as "Coreflood" prior to April 6, 2004, when the alleged theft took place.

Shortly after the wire transfer occurred, a sum of $20,000 was withdrawn from Parex by unknown individuals, according to the complaint filed in court. The remaining $70,000 was, however, frozen by Latvian banking authorities. Bank of America has since settled this case; neither side has revealed the terms.

"I had probably heard the news about Joe Lopez, but (until recently), I hadn't thought twice about the whole Coreflood episode of a few years ago," admitted Joe Stewart, director of Malware Research at SecureWorks, when I spoke to him at last summer's Black Hat conference in Las Vegas.

In particular, Stewart recalled hearing that the U.S. Secret Service had found evidence of Aflood or Coreflood on the Lopez computer.

"The Secret Service actually named Coreflood. That was very surprising. Normally, we don't get the final tally. We don't know who's account got stolen. It's very unusual to actually have a victim that is public, and everybody knows exactly what (was) taken."

Unlike a lot of bots and botnets, most of which exist primarily to relay spam, Stewart said Coreflood has a different agenda: "Its goal is to steal the data directly from users." The much more popular Storm botnet, he said, is more of a nuisance. "Coreflood has a real financial impact for people like Joe Lopez."

Who's behind Coreflood? Stewart declines to say, but in an interview in The New York Times, he suggested that the gang responsible was based somewhere in Russia. He would not tell me the name of the group because of ongoing criminal investigations.

In this video, Stewart talks about what first drew him to study the Coreflood botnet.

When Stewart heard about Lopez, he renewed his research on the Coreflood. With the help of Spamhaus, an antispam organization, Stewart and SecureWorks were able to gain cooperation from a Wisconsin-based provider of one of the command and control centers for the botnet. What he found was not only the bot's source code but also 50 gigabytes of compressed data, searchable in a MySQL database.

Within that database were 378,758 unique bot IDs over a 16-month period. There, for everyone to see, was the time-stamped life cycle--from infection to removal--of each compromised computer. Stewart found the average to be about 66 days.

The graph shows how one state policy agency was infected with Coreflood from April 2007 through January 2008.

(Credit: SecureWorks)

Apparently, Coreflood would enter a network via a drive-by browser exploit, download a copy of the installer, then run PcExec, a legitimate Windows administration tool available from Microsoft.

"It could happen to anybody," Stewart said, "any user who happened to go to the wrong site." If the user also happened to be on the corporate network when that happens, the bot is then able to take advantage of that structure and is able to be a threat to everyone on that network.

"So it's not so much a targeted attack," Stewart said. "But I think they have intentionally set a trap for the domain administrator and are leveraging that in order to have access to the entire company."

Later, the criminal gang responsible for the attack can find out which company it has infected by looking into the registry of the infected computer. "They pull out of the registry a separate request to say who is the registered owner the Windows license. They ship that information back up to the botnet controller."

Just looking at that one C&C server in Wisconsin, Stewart estimates that the gang responsible has infected more than 35,000 domains. It may sell those Web mail accounts to a spammer, because spammers love Web mail accounts. But over the years, Coreflood seems to have targeted only banks. Stewart knows this from the forensic evidence he's collected.

In this video, Stewart talks about digital forensics and what it can tell us about botnets such as Coreflood.

Within the 50GB file, Stewart was able to discern how the thieves culled the data. He said they run a test script against that data that will log via a proxy into the bank using the credentials captured, say, by a keylogging application. The Coreflood script will then capture the HTML data on the post-log-in page.

In most cases, that page also contains the account's bank balance. This is so that after running the test, the hackers have a picture of what the highest dollar amounts are, he said.

"I don't know whether they steal from all of them. We don't have access to the accounts; the bank is not going to tell us how much was stolen out of any given account," he said. "We're not going to get that information, but we know they're actively logging and checking accounts to collect the balance data. The only reason (the script) can see that data is to target the biggest accounts first."

Coreflood does not take a screenshot, Stewart said, but rather scrapes the text out of the HTML. "When they run these tools, it leaves a log file behind, and all the post log-in (data)...are saved in that directory. So we have all of the account balances. So we can parse out what everyone's balance is and see actually how much (the thieves) had access to at any one institution."

In this video, Stewart talks about why Coreflood has been around since 2001, yet hardly anyone has been talking about it.

The problem is that Coreflood has been around since 2001.

"It's unique in that's been around for so long," Stewart said. Moreover, it's unusual that it seems to have been maintained by the same group, "not something that's been sold to another group," as is the case with some botnets.

The way it's managed to evade detection, Stewart said, is that it hasn't really crept high on anyone's list of botnets. "It's not on anyone's radar." Yet it's managed to seriously impact some enterprises that use Windows domains. In companies that have been hit, every employee is potentially sending everything they do back to these guys in Russia.

"To me, (Coreflood) is far more insidious because it doesn't get the attention," said Stewart. Unlike Storm, Coreflood is not constantly in your face. "You're not seeing new social-engineering campaigns every week, not seeing a new news article about it every week talking about all the great innovations the peer-to-peer thing has now. It's been quiet, and just does a few things, and tries not to garner any attention."

So the story of Lopez is significant. It's a tangible event about how online criminals are actually affecting people. It illustrates how much money got taken from an actual bank account, and the real impact on the victim's life. Unfortunately, there are many more botnets--and many more victims to talk about.