Someone once made the comment, “Most people, I think, don’t even know what a rootkit is, so why should they care about it?”
That was in in 2005, when rootkits were an unknown menace for most users. Nowadays, that isn’t quite the case any more, as the number of rootkit infections have exploded in the last few years and lead to more media coverage. In any case, you know a malware has reached evil superstar status when it warrants its own ‘For Dummies’ book.
In the beginning (as in the late 1980s), rootkits were standalone toolkits that allowed hackers to gain root, or administrative access to a computer system (hence the name). Today, the term is usually used to mean programs, codes or techniques that are used to hide malware on an computer.
I’m not going to dwell much on their history or workings (though if you’re interested, Alisa Shevchenko over on Securelist has an excellent article on rootkit history). Instead, I’m going to focus on one particular aspect of rootkits that’s been irritating the daylights out of our Support and Analyst folks recently – why are they so difficult to remove?
Media reports tend to hype ‘rootkits’ as the next big evil in computing, but it’s a bit more complicated than that. For one thing, rootkit tools, coding or techniques aren’t strictly illegal, or even undesirable – perfectly legitimate commercial applications use them to the benefit of users. It also doesn’t help that security vendors don’t have a uniform approach to rootkits; some consider all rootkits as a type of malware, while others shade their evaluations depending on whether the rootkit-like behavior is in a commercial software (in which case, the program may just be potentially unwanted).
Personally, I find it more useful to think of rootkits as operating system controllers. Their entire purpose is to burrow deep into the operating system’s files and subroutines, latching onto and modifying specific processes to gain control over the system. The processes targeted will vary depending on the system and the rootkit in question, but the end result is the same – the rootkit is now in a position to direct the system’s actions for its own ends; it’s become the puppeteer to the computer’s marrionette.
Rootkits have been around a long time, but they only really became a major concern for most users when malware authors found ways to incorporate rootkits into their malicious programs. And for most security professionals, rootkits are considered one of the most troublesome threats to deal with.
A rootkit’s defining characteristic is that it has administrative access – its commands are accepted by the operating system as though they were its own. How this access is gained is another story – a separate trojan may exploit a vulnerability to gain access to a administrator account, or a worm might steal the necessary passwords, any number of things. However the access is gained, the end result is that the rootkit is installed with admin rights, and from there proceeds to do its dirty work.
Rootkits use their privileged access to control the operating system itself, mainly by intercepting and modifying the commands it sends to other programs and basic system activities. Slightly more technically, rootkits usually manipulate various application programming interfaces (APIs), or the subroutines used by the operating system to direct operations (at least, in Windows).
An important point to remember is that these APIs are a built-in features of the operating system. They may be undocumented, or rarely used – but commands made through them are perfectly legitimate, and recognized and treated as such. These APIs can involve and affect every activity performed on the computer, from the mundane (e.g., displaying a folder) to the most fundamental (e.g., booting up).
There are various types of rootkits based on how deeply they can penetrate the operating system to control its most basic processes (if you want to get more technical, Joanna Rutkowska has a good article), but in every case, the key idea is the same – commands sent by the operating system can be viewed and countermanded by the rootkit, if necessary; likewise, requests coming from other programs or system processes are checked and filtered by the rootkit before they reach the operating system.
To illustrate why a rootkit’s manipulation of APIs is significant, let’s compare it to other malwares. When a trojan or virus infects a computer, its interactions with the operating system will usually fall into one of two strategies:
Note that strategy 1 involves the malware functioning just like any other program – its processes and files are visible, the instructions between operating system and program are ‘standard’, and so on. Strategy 2 usually involves some novel technique that forces the system to behave in an unintended manner – ‘breaking the system’, if you like.
Rootkits on the other hand, doesn’t do either. Unlike trojans or viruses, the rootkit doesn’t behave like a separate program being run on top of the operating system; instead, the rootkit acts more like a driver, or one of the operating system’s own components, giving directions on how other programs should be handled. The rootkit also doesn’t exploit any vulnerabilities – it simply uses the operating system’s own features for its own ends.
The thing is, malwares that use Strategies 1 & 2 can be defeated with fairly standard countermeasures: for example, software vendors can release patches to close vulnerabilities, and users can uninstall malicious programs. Rootkits however don’t suffer either problem: there’s no vulnerability that can be patched, and because a rootkit’s first action is usually to hide itself, the rootkit can effectively prevent the user or the operating system from detecting its presence at all, let alone uninstalling it.
The highly technical reason for this is: you can’t remove a file you can’t find. Remember, the rootkit is in control. If the user starts looking through system folders for suspicious files, or starts an antivirus scan, a sophisticated rootkit can display a clean ‘image’ of the infected folder rather than the actual infected one, or move the infected file to another location for the duration of the scan; it can stop the antivirus from running, or force it to report false scan results; anything, really, to prevent detection.
Malware authors really want their creations stay installed and active on your computer, and they can use the rootkit to perform any number of actions to prevent their malwares – or the rootkit itself – from being detected. Some of the tricks they can use to get their way include:
Heck, about the only thing they don’t do is say they love you and will still respect you in the morning.
Antivirus programs have historically had a difficult time dealing with rootkits, precisely because of how they operate: by using the operating system itself to evade detection and prevent removal. In the case of simpler rootkits, it was possible to look for telltale signs – odd changes, missing or alter folders, etc, to determine a rootkit was present. With more sophisticated threats though, detection meant deactivating the rootkit entirely before it could start active evasion; because once it was active, detection and removal became well nigh impossible.
That status quo has changed somewhat in the last few years, as more antivirus vendors have developed the necessary tools to combat the threat. As rootkits themselves vary in complexity, detecting and removing them requires a multi-layered approach:
These detection and removal methods will probably catch most of the rootkits out there, but none of them are 100% certain. In some cases, the fastest, easiest and cheapest possible solution is to simply format and reinstall the entire operating system (assuming of course you have backups of your important files). Determining whether that applies in your case really depends on your personal evaluation of the costs and benefits though, so it’s hard to state any hard and fast rule about this.
Unfortunately, malware authors are ingenious at finding ways to get where they’re not wanted, and the highly complex, multi-layered nature of computing tilts the odds in their favour more than it does to ensuring computer security. Then again, to be fair, humans have lived in houses for thousands of years, and we still haven’t figured out how to totally prevent burglars from invading our homes, so you could probably also credit a natural human genius for finding ways to inconvenience their fellows.
If you’re still interested, here are few other articles with more details (some technical, others less so) about rootkits:
Also partially available in Google Books:
The first known use of the term "trick or treat" was found in a November 1927 edition of Blackie, Alberta's Canada Herald: Hallowe’en provided an opportunity for real strenuous fun. No real damage was done except to the temper of some who had to hunt for wagon wheels, gates, wagons, barrels, etc., much of which decorated the front street. The youthful tormentors were at back door and front demanding edible plunder by the word “trick or treat” to which the inmates gladly responded and sent the robbers away rejoicing. "No real damage" from "youthful tormentors?" Sounds a lot like the early days of hacking. Unfortunately those days are long over. “It’s a business,” F-Secure's Chief Research Officer Mikko Hyppönen told Wired UK. “There’s a whole structure there that’s needed,” F-Secure's "Cyber Gandalf" Andy Patel told ITPRO. “An individual can’t just go in and do this now; it’s not a one man job… these are companies.” The cyber crime "industry" has raked in hundreds of millions and possibly even billions of dollars. And it does it, in general, by counting on people to make mistakes. “People do stupid stuff,” Mikko explained. “You cannot patch people.” The first step to avoiding a threat is knowing it exists. So this Halloween as you search for treats online, look out for these tricks. Ransomware F-Secure Labs has warned about malware that holds your digital files hostage to demand a ransom for most of the last decade. But it's in the last year that the threat has burst into the mainstream and become something you can't go a few weeks without hearing about it on the news. How do you avoid this trick? Keep your system software updated and run security software at all times. Make regular backups of every file that matters on your computer and never click on attachments and links in emails that you weren't expecting. Find My iPhone Scam This scam answers the question, "How can losing your iPhone get any worse?" People who use the "Find My iPhone" app have been targeted by criminals who've gotten ahold of their phones with a scam that allows the crooks to gain access to the device and -- possibly -- the owner's most intimate financial details. How do you avoid this? Check the URL before entering any confidential data. Or as Apple says, "You should never enter your Apple account information on any non-Apple website." Phishing Scams As cyber criminals have gone pro, they've gotten better at using old tactics that we thought had faded away -- like email attachments and phishing scams. Like the trick that gives crooks access to stolen iPhones, a phishing scam just tricks you into entering your private credentials into the wrong site. And it then uses those credentials to hack your email, financial accounts, etc. Checking URLs before entering data is crucial because with the explosion of photo editing software and skills, it's now easier than ever to make a fake site look real. Experts believe that one wrong click to a fake site led the chair of a major presidential campaign to expose his entire inbox to the world. Having someone else leak your password Millions and millions of passwords have been leaked in 2016, some from breaches of data that took place years ago. It might not sound scary that your Yahoo! password from 2005 is now public, except if you are still using that password today on a critical account. This is why you need to use strong, unique password for each important account. Yes, remembering all that is almost impossible. So consider using a tool like F-Secure's KEY to manage your passwords. KEY is free to use on one device. Haunted IoT devices As our homes are getting smarter by connecting almost everything to the internet, they're also getting haunted -- by cyber criminals. A botnet is a network of computers that have been hacked and "enslaved." Security expert Brian Krebs was recently hit by a monster attack on his site that he believes was powered by a botnet powered by "'Internet of Things,” (IoT) devices — routers, IP cameras and digital video recorders (DVRs) that are exposed to the Internet and protected with weak or hard-coded passwords." What can you do? So much of this problem requires manufacturers to improve their security. But you can help by keeping every device updated with the latest software from the manufacturer and always changing your default passwords. [Image by Daniel Lewis | Flickr]
When he was still working in cyber security for the Finnish government, Erka Koivunen met a NATO diplomat that there was "nothing new" about the era we now live in. Foreign envoys have always lived with the constant awareness that their private communications could be "leaked" for their enemies to exploit. "Anything that was written down could eventually be discovered," Erka, who is now an F-Secure Cyber Security Advisor, told me. "So the most sensitive conversations never took place in writing." Given the massive email leaks that have now hit the worlds of business, with the Sony hacks, and politics, with the leaks of U.S. political figures, is this how we should all start thinking? Does everyone alive in the twenty-first century have to operate like a NATO diplomat? Or a C-level executive who knows any word she types could be subpoenaed? Or the campaign chair of a presidential campaign? The answer, unfortunately, seems to be increasingly clear. "Whatever you write, you may need to defend your position in public," Erka said. Relying on an insecure medium The problems with email begin with the general insecurity of it as a means of communication. It's more like sending a postcard than sending a sealed letter, Erka explains. "As soon as the message goes out of your or your company’s systems, you lose control of it," Erka explained. "This is by far the biggest problem of the good-ole-email. Messages can be eavesdropped, altered, delayed, replayed or dropped altogether without you ever knowing." To actually spy on email as it's being transmitted generally requires legal access to telecommunications infrastructure or extraordinary technical knowhow and resources. Think law enforcement or intelligence agencies. Since these groups have a vested interest in cloaking their activities, they had little incentive to engage in the massive sort of leaking of gigabytes of private data we've seen from Wikileaks. However, we appear to be at the end of the era of "the gentleman's agreement" between countries, as cyber policy expert Mara Tam explained on a recent episode of the Risky.Biz podcast. This agreement went something like: "Gentlemen read each other's email, but they don't leak it to the public." The leaks from former CIA contractor Edward Snowden helped make the public aware of how much information the government potentially could access. But the exposure of a private individual's digital communication to the world presents a stark new reality for anyone who conducts business online. "Personal mailboxes store gigabytes’ worth of conversation history that will be a treasure trove for attackers for multiple reasons," Erka said. "There are sensitive discussions about business strategy, customers, competitors, products. There is also internal gossip, badmouthing and other damaging stuff." Activist Naomi Klein told The Intercept that "this sort of indiscriminate dump is precisely what Snowden was trying to protect us from." And we don't yet have a full sense of the potential ways this mass of data can be used against us. A competitor could use private information to tarnish someone’s reputation and hackers can mine the data to prepare for future cyber intrusions or to gain access to your other accounts through password resets. Letting the public decide what's private Leaks have already cost some executives their jobs and could swing the U.S. presidential election. But in a sense, we're all victims of this new risk to all of our privacy. "Whatever you write in an email you have to consider, are you ready for your boss, your spouse, your business partners to read it?" Erka asked. This new reality leads inevitably to the tragedy of self-censorship. Zeynep Tufekci -- a "techno-sociologist" -- has been doing a running commentary on the Wikileaks revelations and is very disturbed by what she's seeing. "People gossiping in internal conversation is not a scandal—but destroying public/private boundaries will paralyze dissent, not the powerful," she tweeted. Wikileaks is releasing more documents than it could ever sift through in the hopes that the newsworthy information will be discerned by interested researchers around the world. But along with potentially relevant items, intensely private information has been revealed. "For example, a suicide attempt was publicized through Podesta indiscriminate dump (Wikileaks tweeted it out)," she noted. "Who will want to be political?" This makes the loss of email seem dire, but perhaps it speaks to a not just a flaw in the medium's security but the medium itself. "The deeper problem with email is that it has never quite settled on a social mode," The New York Times Farhad Manjoo wrote. "An email can be as formal as a legal letter or as tossed off as drive-by insult. This invites confusion." What can you do? So, should you be like that NATO diplomat content to keep all of your deepest secrets out of writing? Can you expect yourself to remove all snark and potentially offensive thoughts from your emails? Should you assume that your email box is like a box of letters in your attic, vulnerable to anyone who can get access to it? These answers are ultimately up to you and how you use -- or don't use -- email. F-Secure security advisor Sean Sullivan has found that young people he's interviewed are increasingly abandoning email as communication tool. "They only have an account -- typically Gmail -- in order to sign up for stuff," he said. If this continues, email is on its way out, whether it's private or not. For now, lawyers, doctors and other professionals with explicit legal responsibilities, email has a much more defined role that cannot be easily abandoned or circumvented. As far as your work email goes, consult your IT staff for guidance as you may be under legal obligation to preserve your data. But for your personal email, Erka suggests you have to at least be aware of how likely you are to be a target and what you can do to contain any potential damage -- besides using a strong unique password for every email account you have and only entering your account information on the secure webpage of your email provider. If you are involved in international politics, for instance, there's no question. You are a target. Hackers are either after your emails or are trying to get access to powerful people in your contacts. If you're someone with no power, no tumultuous relationships and no interest in politics, you're likely not to be on anyone's radar... yet. The problem is no one knows where you'll be in a few years and our inboxes are big enough to last a lifetime. "When everyone is using cloud-based emails like Gmail, there's no need to save space," Erka said. "That's the whole selling point of those services: Never delete anything." If you see the potential for enough damage, you many want these recent leaks as an inspiration to launch a serious spring cleaning of your personal online inboxes, including email and social media. "You may want to delete the messages you don't need and sort the stuff you do want into folders that you take off the web and can store on a secure backup," Erka suggested. Yes, you will lose the convenience of being able to search your Gmail box through a simple interface, but so will potential hackers. He also recommends sharing documents through sharing platforms and cloud services such as Sharepoint, Salesforce or Dropbox. "These links can require separate authentication upon opening and the sender can control how long it will be valid," Erka said. "If the email gets stolen and leaked years later the chances are the link will be invalid by that time." For quick conversations, Sean suggests Wickr, which offers self-destructing messages through a mobile app or a desktop client with easy encryption, something that just doesn't exist for most email. "For professionals, Wickr has a paid service which will retain messages for a legal requirement, and will then securely delete them post-requirement," he said. Regardless of policy, employers have a vested interest in moving their staff away from an over-reliance on email for more than privacy reasons. "Actual phone calls and face-to-face discussions that get out of your chair are probably more useful than email or chat threats," Sean said. "So rather than swap from one to the other – just learn to better utilize what you work with best." These leaks offer a sobering reminder that email is not secure. But, perhaps, the more important message is that it as a means of communication, it was never very smart. [Image by Alan Levine |Flickr]
Cyber security is playing an starring role in the drama surrounding the question of who will be the next president of the United States. "The security aspect of cyber is very, very tough," Republican nominee for president Donald Trump said, when asked about securing American secrets from cyber attacks during the first debate. "And maybe it’s hardly do-able." Even the integrity of the election has been put into doubt by the threat of hacking -- which may be exactly the point. The questions about cyber intrusions into the electoral system and the wild speculations those intrusions provoke can be hard to put in perspective. So here are five basic premises to help you assess the situation as this historic election transpires. It would be almost impossible to hack the entire U.S. election. The biggest reason this U.S. presidential election is unhackable is that most of it doesn't depend on computers. More than three out of four Americans will vote on a paper ballot this November 8, Techcrunch's Ben Dickson reports. And the fact that all Americans don't vote in the same manner points to the biggest reason you probably couldn't hack the election. Each state has its own system, with some federal guidance. Nearly every state lacks sufficient funding to fully upgrade their systems, hence the reliance on outdated technology. So while voting machines are definitely vulnerable to hacking, hitting just the right ones in a systematic way that just happens to sway the electoral college vote in favor of one candidate would involve both a massive investment of time and money and an even larger serving of luck. But that doesn't mean an election can't be "hacked." “To ‘hack’ a US presidential election, all you need to do is to obviously tamper with one county’s system, then leak that the tampering occurred,” our security advisor Sean Sullivan told Dickson. “Many people will rush to assume that all of the other typical issues that occur may also be the result of hacking — and thus, you’ll end up delegitimizing all of the results.” A delegitimized election equals a delegitimized winner. You don't even have to hack an election to hack an election. The hacks of the Democratic National Committee and Hillary Clinton's campaign chair John Podesta could end up being far more consequential in swaying the election than hacking either voting processes or actual vote counts -- especially if the resulting leaks end up revealing something extraordinarily damaging to the candidate in the documents being dripped out by Wikileaks. “Owning an election is gold; being able to influence it is silver; knowing the outcome in advance is bronze,” F-Secure cyber security advisor Erka a Koivunen explained. It's pretty clear that someone is at least after the silver in this election. Someone has definitely poking around in the U.S. election system. The United States has been clear that it believes that Russia is trying to hack this election. This month U.S. officials have explicitly stated that the Russians are behind the hack of a contractor that works on the electoral system of the key swing state of Florida. Similar hacks were reported by the states of Arizona and Illinois. U.S. intelligence also believes Russia is behind the hack of Podesta's emails and a security firm believes it found evidence that the nation led by President Vladmir Putin was behind the hack of the DNC. Russian Foreign Minister Sergei Lavrov told CNN that the accusation that it was behind the Podesta hack "flattering." When pressed to confirm or deny his nation's involvement, Lavrov said, “No, we did not deny this, they did not prove it." Trump himself questioned whether the hack actually happened in the second debate and if he's concerned about Russian hacking, he doesn't seem to be showing it. At one point he even -- jokingly, he said later -- asked Russia to hack his opponent's missing emails. Election technology needs to improve quickly. It's safe to say that no matter who is hacking the U.S. elections, the U.S. is probably hacking them, too. The richest nation on Earth is just not engaging, as far as most people can tell, in the leaks that have followed the recent U.S. hacks. In this new era of cyber attacks backed by nation-states or "privateers" employed by nation-states the rules of cyber espionage are unclear and the fog is thick. No matter what happens in 2016, digital technology will play ever-increasing role in both campaigns and election, and the U.S. needs to take steps to ensure the integrity of its elections. Sullivan believes that the Department of Homeland Security should go through with its proposal to declare voting system critical infrastructure and then adapt its defenses to catch up with the threats. “Network monitoring is rapidly becoming a requirement,” he told Techcrunch's Dickson. And voting must be made to feel at least as secure as using your credit card to buy a coffee. “Smartcard technologies are available in several European countries for online identity authentication,” Sullivan said. “They aren’t widely used. If a country such as the United States were to get serious about rolling out such tech, it would be a game changer.” All of this focus on the security of election systems means that there are “more people checking stuff.” The question now is who is putting in more resources -- the attackers or the people doing the checking. [Image by Maryland GovPics | Flickr]