Category Archives: Spam and scams

Google gets tougher on scammy web sites

If you use Google search (and really, who doesn’t?), you’ve probably noticed the big warnings that appear when you try to click on some search results. That’s Google Safe Browsing (GSB), protecting you from a malicious web site.

GSB flags sites that fail to comply with Google’s Malware, Unwanted Software, Phishing, and Social Engineering Policies.

To get rid of the warning, the owner of a site flagged by GSB must remove objectionable content and resubmit the site for verification in Google Search Console. Until recently, this process could be repeated indefinitely.

To counter repeat offenders, Google has changed the way GSB works. If a web site repeatedly fails to comply with Google’s Safe Browsing policies, it will be flagged as such, and the warning users see will appear for at least 30 days.

In the announcement for this change, Google points out that the new repeat offender policy will not apply to sites that have been hacked (i.e. changed without the owner’s permission).

Ransomware update

Ransomware has been in the news a lot lately. The CryptXXX ransomware is no longer susceptible to easy decryption, and it’s been making a lot of money for its purveryors, in many cases using compromised, high profile business web sites as its delivery mechanism. On a more positive note, the people who created the TeslaCrypt ransomware stopped production and released global decryption keys. New ransomware delivery systems are able to bypass Microsoft’s EMET security software. The Cerber ransomware was recently delivered to a large proportion of Office 365 users via a Word document in an email attachment. And an even more hideous piece of malware surfaced in the last week: posing as ransomware, Ranscam actually just deletes all your files.

Ransomware is different from other kinds of attacks because of the potential damage. It can render all your data permanently inaccessible. Even paying the ransom is no guarantee that you will get all your data back intact. Other types of attacks typically try to fly more under the radar: trojans and rootkits want to control and use your computer’s resources; and viruses want to spread and open the door for other attacks. While other types of attacks can be fixed by removing the affected files, that doesn’t work for ransomware.

Like other types of attacks, ransomware first has to get onto your computer. These days, simply visiting the wrong web site can accomplish that. More common vectors are downloaded media and software, and email attachments. Preventing malware of any kind from getting onto your computer involves the kind of caution we’ve been advising for years; ransomware doesn’t change that advice.

What CAN make a big difference with a ransomware attack is limiting its reach. Once on a computer, ransomware will encrypt all data files it can access; specifically, files to which it has write access. Ransomware typically runs with the same permissions as the user who unwittingly installed it, but more insidious installs may use various techniques to increase its permissions. In any case, limiting access is the best safeguard. For example, set up your regular user so that it cannot install software or make changes to backup data.

Here’s a worst-case scenario: you run a small LAN with three computers. All your data is on those computers. Your backup data is on an external hard drive connected to one of those computers, and a copy exists on the Cloud. For convenience, you’ve configured the computers so that you can copy files between them without having to authenticate. Once ransomware gets onto one of the computers, it will encrypt all data files on that computer, but it will also encrypt data it finds on the other computers, and on the external backup drive. Worse still, some ransomware will also figure out how to get to your cloud backup and encrypt the data there as well.

How to limit your exposure? Require full authentication to access computers on your LAN. Use strong, unique passwords for all services. Store your passwords in a secure password database. Limit access to your backup resources to a special user that isn’t used for other things. In other words, exercise caution to avoid getting infected, but in case you get infected anyway, make sure that you have walls in place that limit the reach of the ransomware.

Most ransomware targets Windows systems, so most of the verbiage out there is about Windows as well. This article covers the basics fairly well.

April security roundup

People who store Slack credentials in Github code repositories learned that this a bad idea, as researchers demonstrated the ease with which this information can be gathered without any explicit permissions.

Scary news: computers at a German nuclear reactor facility were found to be loaded with malware. The only thing that prevented miscreants from playing with real nuclear reactors was the fact that these computers are not connected to the Internet.

Crappy security practices led to the theft of user account information (email addresses and poorly-encrypted passwords) from Minecraft community site Lifeboat.

The notorious hacking group known as Hacking Team made the news again, this time with reports of active drive-by exploits affecting Android devices.

The Nuclear exploit kit is still operating, despite recent, partially-successful, efforts to shut it down. Researchers showed that the kit is still being used, and may be involved in recent ransomware infections.

Good news: the two men responsible for the notorious SpyEye banking trojan, recently extradited to the US to face federal prosecution, will be spending nine and fifteen years in prison.

Zero-day exploits are on the rise, doubling from 24 in 2014 to 54 in 2015. A zero-day exploit is a hack that takes advantage of software vulnerabilities before the software’s maintainers have had a chance to develop a fix.

Cisco security researchers identified vulnerabilities in several enterprise software systems, including Red Hat’s JBoss. As many as three million web-facing servers running this software are at risk of being infected with ransomware, and in fact as many as 2100 infected servers were identified.

More good news: the Petya ransomware was found to contain a flaw that allows its victims to decrypt their data without paying any ransom.

The Mumblehard botnet was taken down by ESet researchers, after it infected at least 4000 computers and sent out countless spam emails.

Microsoft announced plans to prevent Flash content from playing automatically in the Windows 10 web browser Edge. All the major browsers appear to be heading in this direction, if they don’t already have the feature, as does Chrome.

April’s issue of the SANS ‘Ouch!’ newsletter is titled “I’m Hacked, Now What?” (PDF) and provides helpful information for the recently-hacked. The newsletter is aimed at regular users, so it may not be particularly useful for IT professionals, except as a means to educate users.

The wildly popular WhatsApp – a messaging application for mobile devices – now has end-to-end encryption. This will make life more difficult for spy agencies who want to know what users are saying to each other. But WhatsApp users should be aware that this does not make their communications invulnerable, since techniques exist to get around full encryption, such as keystroke loggers.

Bad idea: someone at CNBC thought it would be a good idea to ask users to submit their passwords to a web-based system that would test the passwords and report on their relative strength. The service itself was vulnerable, and exposed submitted passwords to network sniffing. The service was taken offline soon after the vulnerability was identified.

The web site for toy maker Maisto International was hacked and serving up ransomware for an unknown amount of time, probably several days or even weeks. The hack was made possible because the site was using outdated Joomla software.

Security roundup for March 2016

Ransomware made news frequently in March. Two more healthcare networks in the USA were hit with ransomware. A new variety of ransomware called Petya took things to a new level, encrypting the core data structures of hard drives. TeslaCrypt continued its destructive march across Europe and into the USA. A surge in malware-laden advertising (aka malvertising) on several popular web sites, including the Certified Ethical Hacker site, led to numerous ransomware infections.

Smartphones and tablets running Google’s Android operating system remain a popular target for malware. A newly-discovered vulnerability can allow malware to permanently take over a device at the root level. Malware that exploits the still largely unpatched Stagefright vulnerability was identified.

Security researchers discovered malware that can infect computers that are not connected to networks, using external USB devices like thumb drives. The malware, dubbed USB Thief, steals large quantities of data and leaves very little evidence of its presence.

A hacking group known as Suckfly is using stolen security certificates to bypass code signing mechanisms, allowing them to distribute malware-laden apps more effectively.

The folks at Duo Security published an interesting post that aims to demystify malware attacks, describing malware infrastructure and explaining how malware spreads.

Ars Technica reported on the surprising resurgence of Office macro malware. Macros embedded in Office (Word, Excel) documents were a major problem in the 1990s but subsequent security improvements by Microsoft reduced their prevalence until recently. Getting around those improvements only requires tricking the document’s recipient into enabling macros, and it turns out that this is surprisingly easy.

Millions of customer records were made available in the wake of yet another major security breach, this time at Verizon.

Google continued to improve the security of its products, with more encryption, better user notifications and other enhancements to GMail.

Brian Krebs reported on spammers taking advantage of the trust users have in ‘.gov’ domains to redirect unsuspecting users to their spammy offerings.

Opera announced that their web browser will now include ad-blocking features that are enabled by default.

July security roundup

Flash improvements

Adobe is trying desperately to keep Flash viable. In July, they announced structural changes that are expected to strengthen Flash’s overall security. The changes are so far only available in the most recent versions of Chrome, but they are expected to find their way into the other major browsers in August.

Asprox botnet status

There’s an interesting (though technical) overview of recent changes in the behaviour of the Asprox botnet over on the SANS Handler’s Diary. Apparently the botnet is no longer sending malware attachments, and is instead sending pornography and diet-related spam. Comparing my inbox contents with the samples in the linked article, it looks like most of the spam I currently receive is thanks to Asprox. Hopefully Asprox will be targeted by the anti-botnet heavy hitters in the near future.

Flaw in BIND could cause widespread issues

BIND is one of the most common pieces of software on Internet-facing servers. It translates human-readable addresses like ‘boot13.com’ into IP addresses. A bug in version 9 of BIND causes it to crash when a specially-crafted packet is sent to it. Attackers could exploit this bug to execute an effective Denial of Service (DoS) attack against a server running BIND9. Patches have been created and distributed, but any remaining unpatched servers are likely to be identified and attacked in the coming months. Update 2015Aug05: As expected, this bug is now being actively exploited.

Mobile versions of IE are vulnerable

Current, patched versions of Internet Explorer running on mobile devices were recently reported to have four flaws that could allow attackers to run code remotely. Exploits were published, although none have yet been seen in the wild. The vulnerabilities were disclosed by the HP/TippingPoint researchers who discovered them, six months after they privately reported them to Microsoft. Microsoft has yet to patch these vulnerabilities; they apparently feel that vulnerabilities are too difficult to exploit for them to be dangerous.

Stagefright vulnerability on Android devices

A flaw in Stagefright, a core Android software library that processes certain types of media, makes almost all Android phones and tablets vulnerable. The flaw can be exploited as easily as sending a specially-crafted text (MMS) message to a phone, but also by tricking the user into visiting a specific web site. Successful attackers can then access user data and execute code remotely. Unfortunately for users, it’s up to individual manufacturers to develop and provide patches, and this process may take months in some cases. There’s not much users can do to mitigate this problem until patches arrive. Update 2015Aug05: Google is working with its partners to push updates to affected mobile devices.

Mediaserver vulnerability on Android devices

More bad news for Android users: the mediaserver service apparently has difficulty processing MKV media files, and can render a device unusable when it encounters one on a malicious web site. In most cases, the device can be brought back to life by powering it down and back up again.

Android spyware toolkit widely available

And the hits just keep on coming for Android devices. Among the information revealed in the recent Hacking Team breach was the source code for an advanced Android spyware toolkit called RCSAndroid. Like everything else taken from Hacking Team’s systems, this has now been published, and no doubt malicious persons are working on ways to use the toolkit. There’s no easy way to protect yourself from this toolkit, aside from keeping your device up to date with patches. From Trend Micro: “Mobile users are called on to be on top of this news and be on guard for signs of monitoring. Some indicators may come in the form of peculiar behavior such as unexpected rebooting, finding unfamiliar apps installed, or instant messaging apps suddenly freezing.

Avoid Hola’s free VPN service

In the wake of Snowden’s revelations, many people have started using VPN services to encrypt their online activities. Until recently, one popular choice was Hola’s free VPN.

Researchers have discovered that Hola is selling access to the resources of its users, creating what has been described as a botnet, which may have been used for malicious activities.

Hola has been scrambling to deal with the public backlash over this news, but so far all they’ve done is retroactively update their FAQ, adding statements about what Hola can do with your computer if you’ve installed their software.

Recommendation: avoid Hola completely. This kind of deceptive behaviour should not be encouraged. If you’ve been using Hola, check your level of exposure using this handy tool.

Test your skill: spot the phishing email

A short quiz, provided by anti-malware software maker McAfee, allows you to test your skill at identifying phishing email.

In the quiz, you are presented with ten email samples, and asked to decide whether they are phishing email.

What is phishing? From Wikipedia: “Phishing is the illegal attempt to acquire sensitive information such as usernames, passwords, and credit card details (and sometimes, indirectly, money), often for malicious reasons, by masquerading as a trustworthy entity in an electronic communication.

Hint: look for links in each of the sample messages. Hover your mouse over each link, and compare the address with the supposed sender. If a link points to a site that’s unrelated to the supposed sender, the email is probably not legitimate.

Hat tip to reader tap tap.

Google’s efforts to clean up ad injection on the web

A recent post on the Chrome blog discusses Google’s recent efforts to clean up the growing problem of ad injection on the web.

From the post: “Ad injectors are programs that insert new ads, or replace existing ones, into the pages you visit while browsing the web.” If you’re seeing a lot of advertising on all the sites you visit, and much of it seems unrelated to the site, your computer may be running one or more ad injectors.

Ad injectors are unwanted software that is surreptitiously installed on victims’ computers through a variety of tricks, including “marketing, bundling applications with popular downloads, outright malware distribution, and large social advertising campaigns.”

The ad injection ‘ecosystem’ is complex, and at any given time there are thousands of injection campaigns affecting web surfers.

To combat this problem, Google has identified and removed 192 apps – identified as contributing to ad injection systems – from the Chrome Web Store. Improvements in the Chrome Web Store and Chrome itself help to protect against ad injection software. And Google is reaching out to advertising networks, to assist them in eliminating ad injection. Most importantly, Google’s AdWords network policies have been tweaked, to make it more difficult for the perpetrators of ad injection schemes to promote malicious software.

Recent surge in spam likely due to Mumblehard botnet

If you noticed more spam than usual in your inbox in recent months, you’re not alone. You may also have noticed that using your email client to block the sender is typically ineffective. That’s because the spam is coming from thousands of different domains, each corresponding to a different compromised web server.

This is the work of the Mumblehard botnet, which was observed sending mass spam starting about seven months ago by ESet researchers. The Mumblehard code has existed on the web for at least five years, but seems to have started its spamming activities on a large scale only in the last year or so.

Computers infected with Mumblehard are typically Linux web servers. It remains unclear exactly how servers become infected, but researchers suspect that unpatched WordPress and Joomla vulnerabilities provide the key.