The threat to corporate data security is higher than ever, with hackers and other cyber criminals devising ever more complex ways of gaining access to company secrets, employee data, and protected health information. IT security teams now need to monitor and track new threats like never before. Phishing emails must be blocked, employees must be prevented from visiting malicious websites, audits must be conducted to check for malware and viruses, and systems protected against keyloggers and Trojans.
The volume of new malware now being discovered is enough to keep IT security professionals awake at night, with many fearing the security of their systems. IT budgets are strained enough as it is, and the rapidly changing threat landscape is placing those budgets under even greater strain.
What Information are Cyber Criminals Trying to Obtain?
Individual hackers may attempt to break through security defenses for any number of reasons, in fact their aims are not always financially motivated. A grudge may be held against an ex-employer. Business practices may be deemed to be questionable. A company’s carbon footprint may even make it a worthy target for attack. Often the aim is to sabotage, with unscrupulous business competitors willing to employ hackers to enable them to gain a competitive advantage.
However, in the majority of cases, cyber criminals attack companies for the data they hold, which can be sold on to the highest bidder on Darknet websites or used to obtain goods, services, or cold hard cash. Data carries a high value on the black market as it can be used for a myriad of different types of fraud.
Healthcare data can be used to fraudulently obtain medical services. Insurance data used to make bogus insurance claims. Social Security numbers can be used for identity theft or to file false tax returns, and credit card details used to rack up thousands of debts in victims’ names. Corporate secrets such as product development information can be obtained and sold to competitors. The theft of that information can be used by competitors to devastating effect.
Some cyber criminals are not interested in stealing data, just in preventing companies from accessing it. If ransomware can be installed, criminals are able to encrypt an entire system and hold the company to ransom. They will only release the security keys to unencrypt data if a ransom is paid.
How Are Criminals Obtaining the Data?
Spam emails and phishing campaigns (via email, social media networks and over the telephone) are common, although one of the biggest threats to data security comes from malware. If malware can be installed on computers or servers, it can record and exfiltrate data to the hacker’s control centers. All communications can be intercepted and all keystrokes recorded. This enables hackers to obtain login names and passwords: Those used to access internal systems or online bank accounts. It is not just corporate data that is at risk. Any information stored on clients and customers can also potentially be obtained by the attackers.
Common Hacking Techniques Used to Gain Access to Data
Some of the techniques used by hackers to gain access to data include:
Cross Site Request Forgery (CSRF)
Even apparently safe websites can allow hackers to install malware or access sensitive data. This type of attack involves legitimate websites sending requests to other sites. Twitter has suffered cyber attacks involving this method, resulting in logins and passwords of site users being obtained.
Web 2.0 Application Exploits
Take two innocent looking sections of malware code that have been installed on a website. Individually they do no harm, and can easily evade detection. However, when two appear on the same webpage they interact and infect visitors’ devices with malware.
One of the most popular techniques for hacking involves the insertion of meta-characters or SQL commands into input fields on a website. The commands are able to execute back-end SQL code.
All Companies are at Risk, and the Majority Have Already Been Impacted by Malware
If you think only small to medium sized organizations are at risk from malware (due to IT security budgetary constraints) think again. Even the world’s largest corporations are at risk from malware. Earlier this year, Apple was targeted by hackers and suffered a serious malware attack. Full details of the extent of the attack were not disclosed, but a number of Apple Mac computers were compromised by the attackers.
How could the hackers install malware on the computers of such a security conscious company with exceptionally deep pockets? Via a perfectly legitimate website! Users had visited a software development website, with the hackers gaining access via an unpatched Java bug.
The biggest social media sites are not immune to attack either. Twitter suffered a malware attack that exposed the confidential accounts of approximately 250,000 users. This is believed to have happened as a result of the same unpatched Java vulnerability.
No Company is Immune to Cyber Attacks
Around this time last year, a medical equipment manufacturer called Neurocare was targeted by cyber criminals. In that attack, all employees of the organization were affected. In that case, it was not the company’s systems that were attacked directly. The malware came via the company’s payroll processor.
These are all very large companies. But last year hackers used malware to pull of an even bigger and bolder campaign, launching an attack on the International Monetary Fund (IMF). As you could well imagine, the IMF has rather robust security controls in place, yet even they proved no match for the hackers. The attackers just went for the weakest link: IMF employees.
That attack involved spear phishing. Individuals working for the IMF were targeted with a highly convincing campaign which allowed malware to be installed on their computers. That attack was highly sophisticated in nature, and is believed to have been orchestrated by a team of hackers who had received backing from foreign governments. Highly confidential data was exfiltrated in the attack.
Phishing Campaigns Have Proved to be Highly Effective
This year, Kaspersky Labs reported a sizable increase in phishing attacks involving Apple IDs. Two years ago, the average number of attacks per day was just 1,000. Only 12 months later that figure had jumped to 200,000 per day.
Even security firms are not immune to phishing scams. RSA, a prominent American computer and network security company, suffered a phishing attack that was caught by the company’s spam filter. The emails were quarantined, yet were opened from within, unleashing a Trojan that harvested data from employee accounts. RSA’s SecurID tagsix was compromised in that attack.
RSA should not be singled out of course. Even bigger companies have suffered at the hands of phishers. An estimated 20% of Fortune 500 companies have become victims of these campaigns. Even the world’s largest corporations have been hit in recent months. IBM has been affected, and bigger companies still. Microsoft and Google are also victims of phishers.
Beware of Blended Threats Delivered Through Spam Email
The web may now carry the highest risk of malware distribution, but email is still commonly used to deliver malicious software. It remains one of the commonest attack vectors used by phishers. Email spam can be used to attack any device capable of receiving and opening email. This means tablets and Smartphones are vulnerable to attack, not just laptop computers and desktops.
One of the biggest threats comes from blended attacks. These are spam emails that contain links to malicious websites, or even legitimate websites that have been infected with malware. These threats are more difficult to deal with. They require a different form of defense that uses a combination of standard email anti-spam controls along with web security defenses.
Spam may not be the favored choice of hackers these days, but it still represents a serious threat to businesses. Dealing with the emails can waste an extraordinary amount of time and money. Spam can take up huge amounts of bandwidth that affects all employees in a company. Dealing with spam adds significant amounts to operational budgets.
The messages by themselves may not be dangerous, but links to malicious websites can represent a serious problem, especially if staff members have not been warned how to identify malicious links. Infected attachments also place computer systems at risk. Both methods can be used to deliver malware, which has potential to cause a serious amount of damage.
A number of defenses can be used to reduce the risk of malware attacks. Anti-virus software is a must, as is a separate anti-malware shield and scanner. Anti-spam controls are vital, as they can prevent the delivery of phishing emails to employees. Web filtering solutions are also highly beneficial. If a spam email gets through to an endpoint user, the software can prevent a malicious website from being visited.
Unfortunately, there is no single control that can be used to prevent all attacks. The solution is to use multi-layered security defenses and to keep them updated.
A spam filter is one of the best ways to reduce email spam risk; however regardless of whether you choose this important email security measure, there are a number of steps you can take to reduce email spam risk, keep your devices protected, and your valuable data out of the hands of spammers and scammers.
11 Spam Filtering Essentials to Reduce Network Security Risk
Listed below are 11 spam filtering essentials that you can implement to reduce spam volume and the risk of cyber attacks.
1. A Real-Time Block List (RBL) is essential
Spam is commonly sent from a known spam server – one that has been blacklisted, or is known to be used by email spammers. Using a Real-time Block List (RBL) is one of the best protections, that will prevent malicious emails from being delivered to inboxes. This one email security feature has been shown to reduce spam email delivery by 70–90%, and it only takes a few minutes to implement.
Even if you use a spam filter this measure is important. It will reduce the load on your spam filter, email server, and network. An RBL works by blocking messages before they are downloaded, which will also help to save bandwidth. There are a number of ways to do this, although zen.spamhaus.org is one of the best. It is widely regarded as being the best at spam blocking, is updated frequently and importantly boasts a very low false-positive rate.
2. Recipient Verification will block spam sent to invalid email addresses
Spammers like to bombard companies with emails in the hope that some will get through, or that a catch-all is in place and all will be delivered. Common email addresses used are webmaster@, info@, admin@, sales@ etc. etc. These email addresses are commonly used by companies and there is a good chance that they will be delivered to someone. However, you can use Recipient Verification (RV) to reject the bulk of these emails, and only have properly addressed emails delivered.
To do this, use Microsoft Active Directory integration or upload a CSV file of valid email addresses to your spam filter and mail server. This technique will prevent speculative emails from being downloaded and will similarly reduce the load on your spam filter and mail server, and save bandwidth. This method of spam prevention will take longer to complete than setting up your RBL, but it is a worthwhile investment of your time as it will result in a major reduction in spam delivery.
3. Configure your server to require correct SMTP handshake protocols
This is one of the most effective methods of blocking spambots and it will stop the majority of spambot emails from being downloaded and delivered. This is a fairly quick task to complete, and should only take you a few minutes. You will need to set your configuration to require a HELO (EHLO) with a Fully Qualified Domain Name. However, it is important to note that it may be necessary to add some of your suppliers to a whitelist to ensure that their messages do not also get blocked. Not all of your suppliers and contacts will have their own email servers configured correctly, so genuine emails may be caught and blocked. Individual organizations will find this step particularly beneficial. MSPs less so, or not at all.
By using the above three spam prevention methods – which incidentally can be used on virtually all email servers – you will make a considerable bandwidth saving, and dramatically reduce the number of spam emails that are downloaded. This will also help to protect your network from malware. If you allocate just 30 minutes to do all three, it will save weeks of your time, which can be better spent on other cybersecurity tasks.
4. Regularly scan for viruses
A basic security measure is use is a robust and powerful anti-virus program, regardless of whether you use spam filtering. If you don’t implement spam filtering, this measure is especially important, as you are more likely to have viruses delivered to email inboxes.
Even with spam filtering in place, it is also important to have anti-virus software installed and, of course, AV engine and virus definitions need to be kept up to date. Software should be configured to update definitions automatically.
With spam filtering in place, it should be possible to stipulate the update frequency. Be aware that a different anti-virus can be employed to protect endpoints. Using the same AV engine for mail servers and endpoints means that if for any reason your AV software does not detect a virus, all endpoints could potentially be affected. By using a different AV engine for endpoints and mail servers, you maximize the probability of a virus being detected. Fortunately, competition is fierce in this market, so you should not have to pay top dollar to have two different engines in use.
The following steps will apply if you have a spam filter. These will apply no matter which spam filter is used, be that open source, commercial or even cloud-based spam filtering.
5. Certain attachments carry higher risks so block them!
Executable files – those with a .exe suffix – are particularly risky. Fortunately, it is not necessary to run the risk of a user double clicking on them. The best option is to block these file types and other risky file types if they are not typically needed by staff members. Be aware that spammers are sneaky. It is common knowledge that .exe files are risky, so they mask them with other extensions: PDF, XLS, DOC files for example. To counter this, block by MIME type, not by file extension.
6. Take Action to Block Phishing Emails
Phishing emails can easily fool employees into clicking on links that direct them to URLs loaded with malware. There are a number of URLs that are recognized as phishing websites and it is possible to block these quickly and easily. To do this, use SURBL and URIBL lists to check for website domains that frequently appear in unsolicited emails.
7. Ensure that your spam pattern library is regularly updated
You may find that your spam pattern library cannot be configured manually, as this may be hard-wired into your spam filter. Spam signatures are based on a huge database containing recently added spam, as well as past signatures, with the spam-fighting community adding to the database on a daily basis. There are many different resources that can be used, although if you want to ensure you have a fully up to date database of spam signatures, SpamAssassin is arguably the best choice.
8. Bayesian filtering will recognize more spam and block less ham
A Bayes engine is used by most spam filtering engines and can be trained to recognize spam, and differentiate it from ham (i.e. not spam). It is therefore important to use a regularly updated spam pattern library, which will assign incoming emails with a score, in addition to using feedback provided by end users. The Bayes engine learns what is spam and what is not, and will apply the lessons learned to new emails that are received, constantly improving its detection rates to ensure all spam is caught, and false positives are reduced.
9. Stipulate the spam score that is right for your company
As a system administrator you have the power to decide what spam score is right for your company. This will depend on how much risk you want to take. You will find that spam filters will usually allow you to dictate how aggressive they are, although you may find this requires a certain degree of tweaking to ensure that spam doesn’t get through and ham doesn’t get accidently blocked. A spam score is assigned by a number of factors, although the type of attachments and the email content are the two main ways that the spam score is calculated. This process is not particularly time consuming, but bear in mind that the first two weeks after your spam filter has been installed is when this task will need to be completed. Be sure to use your trial period to tweak your spam filter to ensure that spam is blocked and the number of false positives are kept to a minimum.
10. Get your end users working for you
Your spam filter will not always get things right, and some spam and junk emails will slip through the net from time to time. It is therefore useful to instruct end users to manually mark any spam and junk emails received, should they get delivered to their inboxes. End users can help to train your Bayes engine to recognize new spam emails and correct false positives.
11. Provide email security awareness training to employees
Nowadays it is essential that all staff members receive security awareness training. They must be taught how to identify spam emails, phishing campaigns, and potential viruses. They must also be informed of the correct actions to take if they do discover a phishing scam or suspect that an email may contain malware or a virus. Also instruct them on the correct actions to take if they do accidentally open a suspicious attachment.
Is it the job of a system administrator to train employees how to protect themselves and their computers? Arguably it is not, but it can save a lot of headaches down the line. Even a little training can go a very long way. Unfortunately, this is an area of email security that is all too often forgotten.
What is essential, is that employees are aware of the risks of falling for a phishing campaign or downloading malware. In some cases, it could spell the end of a company, and along with it, their jobs. You can always use CryptoLocker to scare employees into paying attention.
Training could well make all the difference. Besides, if you do provide training and employees still take risky actions and infect the network, you will have a clean conscience and can say it is not my fault! And be justified in saying it.
LinkedIn is a social networking website aimed at professionals, which helps them develop contacts, network, get new business, and find new employment opportunities. One of the main purposes of the site is to build up new contacts, making the site perfect for criminals looking to phish for information. The information that can be gathered can be used against individuals – or organizations – to conduct highly convincing spear phishing campaigns.
What is a Spear Phishing?
You may be aware of phishing, a technique used by criminals to get computer users to reveal their login names, passwords, credit card details and other highly sensitive information. Phishing is like using a trawl net behind a boat. The aim is to catch as much as possible. Sooner or later something will swim into the net. With phishing, spam emails are sent out in the millions in the hope that someone will respond. It is a numbers game, and the unwary will be caught.
Spear phishing on the other hand is not random. Individual victims are targeted. Spear phishing campaigns are often very convincing, and emails are sent containing information that is likely to fool a specific individual – or small group of individuals- into revealing passwords, login credentials, security codes or other information. These campaigns are also highly effective at getting users to click links to malicious websites, or open malware-infected email attachments.
How does Spear Phishing Work?
In order to convince users to install malware or reveal their sensitive information, those individuals must be convinced to take a specific action. To increase the chances of that happening, the criminals behind the campaigns need some nuggets of information. These could be gained from social media websites. People reveal a wealth of information about themselves on Twitter and Facebook, and some leave their accounts open for anyone to see.
LinkedIn is similarly being used by hackers to gain information about users, with the data harvested being utilized in future phishing and spamming campaigns. Data is collected on users, and used to devise phishing emails containing malicious software or links to malware-infected websites, or fake websites which convince users to enter in their sensitive details.
LinkedIn Used by Scammers to Gather Sensitive Data
One of the latest scams identified involves the creation of fake LinkedIn contacts. Accounts are created by scammers, and then used to make connections with people in similar industries. Unfortunately, connecting with these individuals will allow them to obtain a wealth of information on you, such as your employment and education history, phone numbers and whatever information you add to your profile. In many cases, you will be supplying your entire CV to a hacker by accepting them as a contact. Fake LinkedIn contacts are now a major problem as they pose a big security risk.
This means that every contact must be vetted and assessed before you agree to a connection, and who has the time to do that?
How to Spot Fake LinkedIn Contacts
Fortunately, there are some common tells, and a little research (even a couple of minutes) can reveal fake LinkedIn contacts.
No photograph has been added
LinkedIn is all about making professional contacts. Photographs are therefore essential. People like to see who they are connecting with. If no photograph has been added, treat the account with extreme suspicion. Would the CEO of a mining company really be that concerned about someone finding out what he or she looks like?
Stock Photographs Used
Stock photographs can be purchased from image libraries for cents. Complete a quick Google image check against the user’s name and photo. If they are interested in business networking, their photo is likely to appear on other websites. If it appears under a different name, you will know the account is a fake.
Stolen Photographs Used
A photo search can reveal quite a lot of information about the genuineness of a contact. If your prospective contact is a librarian, it is perhaps unlikely they will also be a Ukrainian heavyweight boxing champion (Not necessarily of course!)
Numerous fake accounts have been created with the individuals claiming to be directors of companies. By day, they are the CEO of two or three different companies, by night they supplement their income by producing internet porn (Images have been taken from adult sites and used for LinkedIn). Unlikely perhaps, that CEOs would feel the need to do this.
Some fake LinkedIn accounts are very convincing
Not all fake LinkedIn accounts are suspicious. Many have extensive contacts, and a realistic profile. However often times that information has been lifted from other websites. Sometimes a photo will not have been used elsewhere online, but frequently the text has. One way of checking is to cut and paste small section of their profile and pasting it in Google. It may reveal that the data has been copied from a legitimate LinkedIn account or other social media site.
What is the Risk of Connecting with Fake LinkedIn Contacts?
There are a number of reasons why criminals go to the trouble of creating fake LinkedIn contacts. Spammers can use LinkedIn to obtain email addresses. Criminals can gain information to launch phishing campaigns and information can be gathered to commit identity theft. If a scammer can convince you they are genuine, they may create a fake job for you and get you to reveal some very sensitive information.
Of course the only way to be sure that you are not accepting fake LinkedIn contacts is to only connect with people you know, but that kind of defeats the whole purpose of the website. The answer is therefore to conduct a rudimentary check to make sure the person you are about to share information with is in fact genuine.