… they are used to stealing candy from a baby!

Security Alert: Calls announcing lottery/other prizes & demanding processing fees via TV recharge coupons/other modes are fraudulent. Please ignore such calls.

The above warning was issued recently by my mobile phone service provider. It came a few days after I received a couple of text messages related to winning a gigantic monetary prize in the UK similar to the ones described several months ago.

Given that the mobile service provider felt the need to send out a mass warning suggests that several people have already been duped into parting with financial resources (err … “TV recharge coupons” … wow .. I think!?), and have complained bitterly to the powers that be.

If people, especially those in India, have been duped it is a cause for concern since the level of social engineering involved in these fraudulent campaigns is far from sophisticated. As mentioned in the previous blog, the reference to all things British in a message sent to an Indian mobile ought to raise more than a few eyebrows, rather than raise funds for the bad guys.

As the mobile service provider suggests, these types of messages purporting to provide prize money without any effort on your part, ought to be treated with the scorn they deserve, and simply ignored. Please remember, if something sounds too good to be true, it usually is.

Image courtesy of anthonyluis.hasaportfolio.com

Samir Mody

Senior Manager, K7TCL

‘It has been said that arguing against globalization is like arguing against the Laws of Gravity’ – Kofi Annan (former UN Secretary General).

It appears malware writers have begun to take globalization to heart. You might recall an earlier blog post which highlighted the fact that malware authors were failing to tailor their malware to the OS locale. They seem to be learning and correcting their errors.

Here at K7TCL we came across a malware sample that upon execution seems like yet another example of ransom-ware (Winlocker to be specific). The malware displays a fake system crash message as shown below:

It is unlikely to matter to a layman but FYI the memory address 0x3BC3 is in the range generally reserved for MS-DOS features rather than modern system process code so, from a technical viewpoint, the message is clearly bogus.

In the above case access to the computer is denied until the victim enters a ‘deactivation key’, which needs to be requested from the attacker, by dialing telephone numbers that seem to originate from the African continent.

Interestingly, examining the strings inside the malware reveals that the above fake message is available in several languages. Playing around with the ‘Regional and Language Options’ in control panel and then executing the malware resulted in the following:

French:

German:

Indonesian:

From the above screen shots it is clear that malware authors are investing significant resources in creating the world’s local malware. By covering a few more languages, the malware authors have now managed to expand their potential targets across multiple continents, thereby probably increasing their revenue by several folds.

One can only speculate about the stage at which the victim loses his/her money, whether on entering the ‘deactivation key’ the malware would actually release the system, and whether the malware would return at a later stage to trouble the user some more.

This threat is detected as Password-Stealer (0028ee481) by K7 Total Security.

Kaarthik R.M
K7TCL

Social engineering is the art of manipulating people’s behaviour. Some malware authors rely on social engineering to disguise their code and get it executed on a user’s machine. A key element of a successful malware campaign, which relies on social engineering to lure its victims, is the visual appeal of the attack. Under the right circumstances, a malware which is strikingly similar to a file it is trying to impersonate, is more likely to get executed by a naive user.

Fake Anti-Virus malware authors, for example, are known to put in considerable effort to make their scare ware messages look more authentic. We had blogged about one such sample, which even goes to the lengths of copying malware descriptions from security vendors’ websites, in order to get the user into executing it.

Recently, we came across a website which takes this visual aspect of social engineering quite seriously. The site under discussion, www.vista.[Removed] claims to provide a number of [already freely available] applications for download. Here’s a brief list of the files that were distributed from this site over the last week:

• Divx.exe
• MySQL.exe
• VideoLAN.exe
• WinPcap.exe

To boost the chances of having the files downloaded and executed, each software listed in the site has a brief description of itself, screen shots, user reviews, comments etc. It appears that the author of the site has spared no expense, at least in terms of effort, in plagiarizing the content from other genuine software distribution sites, making the site appear as legitimate as possible, to lure people into downloading and executing the files.

Not all that glitters is gold though. Closer inspection reveals that all files downloaded from this site are around 2.5 MB in size and on execution, the files prompt the user to send an SMS to a premium rate number, from which a reply is sent back with a code to unlock and install the applications. While the files don’t do any damage to the user’s computer, the innocent user still ends up getting charged for the premium rate SMS that was probably sent. One can only assume that this site could be a landing page for a broader attack scheme.

Social engineering (not to be confused with social networking!) based on PEBCAK (Problem Exists Between Chair And Keyboard) is a very potent weapon for effecting malware execution on various operating systems, including those on mobile devices such as Android. It thrives on temptation, ignorance, and fear on the part of the victim. Even though descriptions of social engineering are ubiquitous and some may consider the topic to be mundane, we at K7TCL feel it our duty to keep the general public at large informed about the use and abuse of social engineering so that users are less likely to be seduced by malware authors. Do not invite the thief through your front door.

Image Courtesy of www.publicdomainpictures.net

Lokesh Kumar
K7TCL

In the modern, professional threat landscape there is still room, albeit tiny, for malware which is written by the proverbial ‘script-kiddy’. As a case in point we do continue to very occasionally see autorun worms written in Visual Basic Script, and of course we ensure that they are detected.

The issue is that the allowance for malware written by novices can lead to consternation when a judgement call needs to be made on the status of a file. Recently we at K7TCL encountered a VBS file which removes a particular Anti-Virus vendor’s security product without requesting prior confirmation. This harked back to the old days of DOS BAT file Trojans which ran commands such as ‘DELTREE /Y’, ‘DEL *.* /Y’ and ‘FORMAT /Q’, to the, presumably, eternal amusement of the script-kiddy who arrogates kudos. However, the VBS file in question could also very well have been written quite legitimately by Technical Support personnel of a competing security company to avoid conflicts between Anti-Virus products, i.e. one product may need to be uninstalled before another can be installed. The decision-making process on the file was further complicated by the fact that several other security products classified it as a ‘kill AV’ Trojan. “Malware or not malware?”, that was the question.

Take it from us, proving that a clean file is actually clean is not always an easy task. On the contrary, it is generally far from straightforward. Many a time it depends on skill, wit and judgement. In the case of our candidate VBS file we decided against detecting it. This was primarily because we recognised that its functionality could not be considered inherently malicious. In addition, quite importantly, the coding style with variable names, etc, seemed to suggest that the script was not written by a trouble-maker, but rather by somebody who perhaps ought to have been a little more careful about requesting user interaction before deleting things. An additional comment explicitly stating the origin of the file and the purpose of the code would have been ideal. The concept of ‘perceived intent’ was the ultimate arbiter in the decision-making process.

Image courtesy of www.clker.com

Samir Mody
Senior Manager, K7TCL

A digital signature applied to an object is meant to verify that the object comes from a known source, and also that the file has not been tampered with subsequently. In addition, the source of the software would have been registered with a well-known certificate authority which confers on the source an aura of legitimacy, and thus a vicarious trust on the signed object.

The mere presence of a digital signature, however, does not intend that the file in question is clean. Malware authors can and do exploit the misconception of trust associated with digital signatures to defraud the user into running their wares. The Zeus family of malware, for example, used self-signed certificates masquerading as a certificate from a legitimate company. The Stuxnet malware generated digital signatures using stolen private keys.

When legitimately signed software exhibit questionable behaviour, it leads to complications. Such applications come from software distributors who digitally sign their code and make it appear clean by bundling them with other legitimate applications. A colleague from the Anti-Virus community had recently blogged about one such software distributor – Pinball Corp., whose software displays dubious behaviour. The software comes bundled with installers for legitimate media related software like:

• XVid Codec
• FLV Codec
• VLC Player etc.

At K7TCL, we’ve been noticing that these digitally signed installers come with a new checksum almost everyday over the last couple of months, and that this trend is still continuing. One wonders why a company claiming to distribute legitimate applications would employ:

• Server-side polymorphism – A technique used by malware authors to avoid being detected by security vendors
• Missing codec scam – A social engineering technique used by malware authors to lure victims into running files

The ethical use of digital signatures states that a digital certificate can be revoked if mis-representation of software behaviour is suspected. But what constitutes this mis-representation? It seems that either the certificate issuing authority is unaware of this abuse, or perhaps it is aware, but is unwilling to act upon it. Either way, the security vendors may be left with no choice but to take matters into their own hands. These files, despite having a legitimate digital signature, are detected as Adware/Spyware by most Anti-Virus vendors.

Lokesh Kumar
K7 TCL

Recently we received an email from the RBI (Reserve Bank of India), or so it claims to be, regarding a ‘One Time Password’ registration.  This ended up in the spam folder. Let us see why.

Here is the email in question:

• The source of this email (highlighted green) is ‘rbi.org.in’ which is not suspicious but is probably spoofed.
• It informs us to ignore any warning (highlighted red) that the email client might give us. This is suspicious.
• The attachment (highlighted cyan) has a double extension. This is clearly suspicious.

There is even a tail-piece of advice to ‘Beware of Phishing’ to make the user feel good about the message. After all, no thief warns you about impending thievery, right? Wrong!

Once you download and open the attachment you are directed to the following page:

This looks like a normal RBI page. But a closer look at the address reveals for a fact that this not an RBI page. It is a login page but it is not secure, and there is no ‘https’ authentication. This is a cleverly constructed page. Only the ‘Login ID’ and the ‘Password’ fields are custom made. The rest is ‘borrowed’ from the actual RBI site, therefore clicking on any of the menu items would still take you to the valid RBI page.

Let us check what is inside the attachment:

This URL has quite a number of sub-domains (grayed out for security reasons), none of which is even remotely related to the RBI. This is highly suspicious. Double-clicking on the attachment would take you to the page shown above which masquerades as a  bona fide RBI site.

Let us start filling in the form with some fake details:

Once you fill in the details and click next you will be taken to the following page wherein you’ll be asked to fill in your transaction password and mobile number:

Once you click submit it throws a message that the registration is successful. But there was no actual password registration done during the entire exercise. The mail states an additional password is to be created, which was never done here. Whenever a new password is created any valid system would ask you to confirm your password, which was not the case here. Hence this is a clear attempt to phish out confidential details.

The network captures of the above exercises show the password and user names being sent over the Internet as plain text messages:

Never would your bank send your banking credentials as plain text. They are always sent over a secure connection in an encrypted format.

At the time of writing the attack domain was still live. To avoid being a victim of such social engineering attacks, the solution to a large extent still rests with the user, even though URL filtering and phishing heuristics do thwart many of these attempts at phishing. Please read through one of the earlier entries to find out how to recognize and stay away from phishing scams – ‘Teach a Man to Anti-Phish’

Kaarthik R.M
K7 TCL

A few months ago we highlighted the complications that could arise when different families of malware interact with each other. These scenarios take place on a regular basis, and for the most part involve file infectors, i.e. the quintessential “virus” type, which latch their code on to host executable files. Multiple infections of a given host, especially by different families of viruses, seriously complicate the process of disinfection to restore a suitable version of the original file. Let us take a brief look at the technical reasons for these complications.

There are two main issues. The first is that viruses can interfere with each other to the extent that the original host file is permanently damaged, i.e. “corrupted”. This happens because most virus authors do not expect to infect a host which has already been infected with another file infector, and therefore do not design their code to deal with these scenarios. Consequently certain assumptions about the suitable physical characteristics of a host file to be infected may not hold true (hosts infected by a virus generally look very different when compared to typical clean files), and a subsequent infection simply breaks the erstwhile executable file. Of course, it is not straightforward to determine that a host file already contains a virus infection, especially if the infection involves function patching (aka mid-infection) rather than the far more common entrypoint change. One must also avoid confusing a host which appears odd due to its legitimate packer rather than due to a virus infection.

The second issue is somewhat related to the first, but from the perspective of making disinfection far more difficult, even when it is possible. The reason for this is that a disinfection routine, a very delicate process, almost always has to be exactly tailored to the specific virus at hand, with concomitant assumptions about the physical changes which require remediation. It is virtually impossible to reliably predict the presence of another virus infection, much less the specific virus family involved. Under these circumstances of multiple cross-family infections, any assumptions made in the disinfection routine for a known virus layer could be null and void, resulting in the attempted disinfection failing, or far worse, corrupting the file on which the operation is being performed.

The high prevalence of multiply-infected host files in India indicates the ubiquitous nature of several virus families vying for supremacy. There may also be the suggestion that users are not rigorous enough about keeping their Anti-Virus solution completely up-to-date since some of the virus infections seen involve “ancient” families which have been protected against for several years. Our usual sentiments about keeping one’s security solution up-to-date apply.

Samir Mody
Senior Manager, K7TCL

Malware authors have long realized that implementing scare tactics to rip people off their money works. Why waste time finding a new vulnerability to spread malware when you can scare people into downloading and running it? For a while now, fake anti-virus malware has been one of the top revenue generators for the malware authors.

Lately however, users have turned vigilant towards such fraudulent security tools and simply ignore the spurious warnings. The malware authors, who have realized this, have upped their game by changing the scareware reports to involve hard drive failures rather than virus infections.

Over the last month, K7TCL noticed a steady rise in the number of samples arriving with the name “pusk.exe” from various sources. Closer analysis of one sample revealed that this was a fake disk diagnostic tool. On installation the malware displays the following message:

The malware then goes on to display fake disk diagnosis messages:

It’s no surprise that when the users click on the “Fix Errors” dialogue box, they see the message below:

These samples are detected generically as “Trojan (0026b5241)”.

Lokesh Kumar
K7TCL

Miscreants are always geared up to start a new wave of spam and malware campaign. When a sensational event occurs, users tend to go searching for news on the event, making it easy for the criminals  to do what they do best.

Case in point, last week saw the Internet abuzz with news regarding Osama Bin Laden’s death.  Some research into the user’s search behavior from Google trends revealed that the maximum number of searches were for the keyword “Osama” and the maximum number of searches arrived from the United States.

The second to top the list was India, with Tamil Nadu leading the way, closely followed by Karnataka.

The bad guys tried to capitalize on this news by poisoning search results, spreading malware & spam. They setup fake videos, facebook wall posts, websites, all claiming to reveal “exclusive” information on the death of Al-Qaeda’s top man, thus enabling them to invite potential victims to their trap.

Out of approximately 1,00,000 videos uploaded to date on You-tube with the keyword “Osama”, around 23,000 were uploaded just in the past week.

Also, there were around 1,300 websites registered, in the first 3 days since the news emerged, relating to Osama’s death.

Out of these newly registered websites, the maximum number of registrations was made with the registrar “1 & 1 Internet AG”, followed by namecheap.com.

Queries in domain reputations sites like www.malwareurl.com indicate that both registrars had hosted sites that have spread exploits & spam before.

Lokesh Kumar
K7 TCL

Top level domains (TLD) refer to the suffix attached to domain names on the Internet. A site ending with .com, for example, is meant for websites used for commercial purposes. Similarly, country code top level domains (CCTLD) are meant to denote the country from which a website originates. A site ending with “.in”, for example, is meant for websites from India.

However, lenient CCTLD registration rules have meant that this is not always the case. Sites using CCTLD for purposes other than to denote their origin country have been garnering popularity for a while now. For example, “.fm” is a CCTLD assigned for the federal states of Micronesia. “.fm” which also is an acronym for “frequency modulation”, and is commonly used by radio websites which don’t originate from Micronesia. Similarly “.in” which refers to the CCTLD for India, could also mean “Internet” or “international”. When it comes to registering websites using the CCTLD, the cloud is the limit. Websites like “icome.in/peace”, “rest.in/peace”, for example, don’t just read well but are also easy for potential customers to remember. Apart from this, CCTLD from India are relatively cheaper to register than registering CCTLD from other countries.

While such use of CCTLD has its advantages, it also comes with its share of disadvantages. The number of CCTLD used by malware authors & spammers to lure victims to their sites is steadily on the rise. A simple query for malicious sites which use a CCTLD of “.in” from malwareurl.com resulted in a significant number of hits, as shown below:

Although none of the sites above are active anymore, a closer look reveals that they all originate from the same IP address and spread the same malware.

Users ought to be aware of such sites which pretend to come from one country, when in fact they don’t. Simple networking tools like whois will provide more information on the origin of the website. Also, the INRegistry tightening its registration rules should help significantly reduce the amount of spam and malware that originate from this CCTLD.

Lokesh Kumar
K7TCL