Entries Tagged "phishing"

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Cybersecurity During COVID-19

Three weeks ago (could it possibly be that long already?), I wrote about the increased risks of working remotely during the COVID-19 pandemic.

One, employees are working from their home networks and sometimes from their home computers. These systems are more likely to be out of date, unpatched, and unprotected. They are more vulnerable to attack simply because they are less secure.

Two, sensitive organizational data will likely migrate outside of the network. Employees working from home are going to save data on their own computers, where they aren’t protected by the organization’s security systems. This makes the data more likely to be hacked and stolen.

Three, employees are more likely to access their organizational networks insecurely. If the organization is lucky, they will have already set up a VPN for remote access. If not, they’re either trying to get one quickly or not bothering at all. Handing people VPN software to install and use with zero training is a recipe for security mistakes, but not using a VPN is even worse.

Four, employees are being asked to use new and unfamiliar tools like Zoom to replace face-to-face meetings. Again, these hastily set-up systems are likely to be insecure.

Five, the general chaos of “doing things differently” is an opening for attack. Tricks like business email compromise, where an employee gets a fake email from a senior executive asking him to transfer money to some account, will be more successful when the employee can’t walk down the hall to confirm the email’s validity—and when everyone is distracted and so many other things are being done differently.

NASA is reporting an increase in cyberattacks. From an agency memo:

A new wave of cyber-attacks is targeting Federal Agency Personnel, required to telework from home, during the Novel Coronavirus (COVID-19) outbreak. During the past few weeks, NASA’s Security Operations Center (SOC) mitigation tools have prevented success of these attempts. Here are some examples of what’s been observed in the past few days:

  • Doubling of email phishing attempts
  • Exponential increase in malware attacks on NASA systems
  • Double the number of mitigation-blocking of NASA systems trying to access malicious sites (often unknowingly) due to users accessing the Internet

Here’s another article that makes basically the same points I did:

But the rapid shift to remote working will inevitably create or exacerbate gaps in security. Employees using unfamiliar software will get settings wrong and leave themselves open to breaches. Staff forced to use their own ageing laptops from home will find their data to be less secure than those using modern equipment.

That’s a big problem because the security issues are not going away. For the last couple of months coronavirus-themed malware and phishing scams have been on the rise. Business email compromise scams—where crooks impersonate a CEO or other senior staff member and then try to trick workers into sending money to their accounts—could be made easier if staff primarily rely on email to communicate while at home.

EDITED TO ADD: This post has been translated into Portuguese.

EDITED TO ADD (4/13): A three-part series about home-office cybersecurity.

EDITED TO ADD: This post has been translated into Spanish.

Posted on April 7, 2020 at 10:00 AM • View Comments

Emotet Malware Causes Physical Damage

Microsoft is reporting that an Emotet malware infection shut down a network by causing computers to overheat and then crash.

The Emotet payload was delivered and executed on the systems of Fabrikam—a fake name Microsoft gave the victim in their case study—five days after the employee’s user credentials were exfiltrated to the attacker’s command and control (C&C) server.

Before this, the threat actors used the stolen credentials to deliver phishing emails to other Fabrikam employees, as well as to their external contacts, with more and more systems getting infected and downloading additional malware payloads.

The malware further spread through the network without raising any red flags by stealing admin account credentials authenticating itself on new systems, later used as stepping stones to compromise other devices.

Within 8 days since that first booby-trapped attachment was opened, Fabrikam’s entire network was brought to its knees despite the IT department’s efforts, with PCs overheating, freezing, and rebooting because of blue screens, and Internet connections slowing down to a crawl because of Emotet devouring all the bandwidth.

The infection mechanism was one employee opening a malicious attachment to a phishing email. I can’t find any information on what kind of attachment.

Posted on April 6, 2020 at 11:26 AM • View Comments

Deep Learning to Find Malicious Email Attachments

Google presented its system of using deep-learning techniques to identify malicious email attachments:

At the RSA security conference in San Francisco on Tuesday, Google’s security and anti-abuse research lead Elie Bursztein will present findings on how the new deep-learning scanner for documents is faring against the 300 billion attachments it has to process each week. It’s challenging to tell the difference between legitimate documents in all their infinite variations and those that have specifically been manipulated to conceal something dangerous. Google says that 63 percent of the malicious documents it blocks each day are different than the ones its systems flagged the day before. But this is exactly the type of pattern-recognition problem where deep learning can be helpful.

[…]

The document analyzer looks for common red flags, probes files if they have components that may have been purposefully obfuscated, and does other checks like examining macros­—the tool in Microsoft Word documents that chains commands together in a series and is often used in attacks. The volume of malicious documents that attackers send out varies widely day to day. Bursztein says that since its deployment, the document scanner has been particularly good at flagging suspicious documents sent in bursts by malicious botnets or through other mass distribution methods. He was also surprised to discover how effective the scanner is at analyzing Microsoft Excel documents, a complicated file format that can be difficult to assess.

This is the sort of thing that’s pretty well optimized for machine-learning techniques.

Posted on February 28, 2020 at 11:57 AM • View Comments

Real-Time Attacks Against Two-Factor Authentication

Attackers are targeting two-factor authentication systems:

Attackers working on behalf of the Iranian government collected detailed information on targets and used that knowledge to write spear-phishing emails that were tailored to the targets’ level of operational security, researchers with security firm Certfa Lab said in a blog post. The emails contained a hidden image that alerted the attackers in real time when targets viewed the messages. When targets entered passwords into a fake Gmail or Yahoo security page, the attackers would almost simultaneously enter the credentials into a real login page. In the event targets’ accounts were protected by 2fa, the attackers redirected targets to a new page that requested a one-time password.

This isn’t new. I wrote about this exact attack in 2005 and 2009.

Posted on December 14, 2018 at 10:02 AM • View Comments

Sophisticated Voice Phishing Scams

Brian Krebs is reporting on some new and sophisticated phishing scams over the telephone.

I second his advice: “never give out any information about yourself in response to an unsolicited phone call.” Always call them back, and not using the number offered to you by the caller. Always.

EDITED TO ADD: In 2009, I wrote:

When I was growing up, children were commonly taught: “don’t talk to strangers.” Strangers might be bad, we were told, so it’s prudent to steer clear of them.

And yet most people are honest, kind, and generous, especially when someone asks them for help. If a small child is in trouble, the smartest thing he can do is find a nice-looking stranger and talk to him.

These two pieces of advice may seem to contradict each other, but they don’t. The difference is that in the second instance, the child is choosing which stranger to talk to. Given that the overwhelming majority of people will help, the child is likely to get help if he chooses a random stranger. But if a stranger comes up to a child and talks to him or her, it’s not a random choice. It’s more likely, although still unlikely, that the stranger is up to no good.

That advice is generalizable to this instance as well. The problem is that someone claiming to be from your bank asking for personal information. The problem is that they contacted you first.

Where else does this advice hold true?

Posted on October 2, 2018 at 3:09 PM • View Comments

Detecting Phishing Sites with Machine Learning

Really interesting article:

A trained eye (or even a not-so-trained one) can discern when something phishy is going on with a domain or subdomain name. There are search tools, such as Censys.io, that allow humans to specifically search through the massive pile of certificate log entries for sites that spoof certain brands or functions common to identity-processing sites. But it’s not something humans can do in real time very well—which is where machine learning steps in.

StreamingPhish and the other tools apply a set of rules against the names within certificate log entries. In StreamingPhish’s case, these rules are the result of guided learning—a corpus of known good and bad domain names is processed and turned into a “classifier,” which (based on my anecdotal experience) can then fairly reliably identify potentially evil websites.

Posted on August 9, 2018 at 6:17 AM • View Comments

Google Employees Use a Physical Token as Their Second Authentication Factor

Krebs on Security is reporting that all 85,000 Google employees use two-factor authentication with a physical token.

A Google spokesperson said Security Keys now form the basis of all account access at Google.

“We have had no reported or confirmed account takeovers since implementing security keys at Google,” the spokesperson said. “Users might be asked to authenticate using their security key for many different apps/reasons. It all depends on the sensitivity of the app and the risk of the user at that point in time.”

Now Google is selling that security to its users:

On Wednesday, the company announced its new Titan security key, a device that protects your accounts by restricting two-factor authentication to the physical world. It’s available as a USB stick and in a Bluetooth variation, and like similar products by Yubico and Feitian, it utilizes the protocol approved by the FIDO alliance. That means it’ll be compatible with pretty much any service that enables users to turn on Universal 2nd Factor Authentication (U2F).

Posted on July 26, 2018 at 12:18 PM • View Comments

Obscure E-Mail Vulnerability

This vulnerability is a result of an interaction between two different ways of handling e-mail addresses. Gmail ignores dots in addresses, so bruce.schneier@gmail.com is the same as bruceschneier@gmail.com is the same as b.r.u.c.e.schneier@gmail.com. (Note: I do not own any of those email addresses—if they’re even valid.) Netflix doesn’t ignore dots, so those are all unique e-mail addresses and can each be used to register an account. This difference can be exploited.

I was almost fooled into perpetually paying for Eve’s Netflix access, and only paused because I didn’t recognize the declined card. More generally, the phishing scam here is:

  1. Hammer the Netflix signup form until you find a gmail.com address which is “already registered”. Let’s say you find the victim jameshfisher.
  2. Create a Netflix account with address james.hfisher.
  3. Sign up for free trial with a throwaway card number.
  4. After Netflix applies the “active card check”, cancel the card.
  5. Wait for Netflix to bill the cancelled card. Then Netflix emails james.hfisher asking for a valid card.
  6. Hope Jim reads the email to james.hfisher, assumes it’s for his Netflix account backed by jameshfisher, then enters his card **** 1234.
  7. Change the email for the Netflix account to eve@gmail.com, kicking Jim’s access to this account.
  8. Use Netflix free forever with Jim’s card **** 1234!

Obscure, yes? A problem, yes?

James Fisher, who wrote the post, argues that it’s Google’s fault. Ignoring dots might give people an enormous number of different email addresses, but it’s not a feature that people actually want. And as long as other sites don’t follow Google’s lead, these sorts of problems are possible.

I think the problem is more subtle. It’s an example of two systems without a security vulnerability coming together to create a security vulnerability. As we connect more systems directly to each other, we’re going to see a lot more of these. And like this Google/Netflix interaction, it’s going to be hard to figure out who to blame and who—if anyone—has the responsibility of fixing it.

Posted on April 9, 2018 at 6:30 AM • View Comments

Google's Data on Login Thefts

This is interesting research and data:

With Google accounts as a case-study, we teamed up with the University of California, Berkeley to better understand how hijackers attempt to take over accounts in the wild. From March 2016 to March 2017, we analyzed several black markets to see how hijackers steal passwords and other sensitive data.

[…]

Our research tracked several black markets that traded third-party password breaches, as well as 25,000 blackhat tools used for phishing and keylogging. In total, these sources helped us identify 788,000 credentials stolen via keyloggers, 12 million credentials stolen via phishing, and 3.3 billion credentials exposed by third-party breaches.

The report.

Posted on November 13, 2017 at 6:11 AM • View Comments

Google Login Security for High-Risk Users

Google has a new login service for high-risk users. It’s good, but unforgiving.

Logging in from a desktop will require a special USB key, while accessing your data from a mobile device will similarly require a Bluetooth dongle. All non-Google services and apps will be exiled from reaching into your Gmail or Google Drive. Google’s malware scanners will use a more intensive process to quarantine and analyze incoming documents. And if you forget your password, or lose your hardware login keys, you’ll have to jump through more hoops than ever to regain access, the better to foil any intruders who would abuse that process to circumvent all of Google’s other safeguards.

It’s called Advanced Protection.

Posted on October 30, 2017 at 12:23 PM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.