Bitcoin phishers get desperate with search engine ads

More than a week after we reported deceptive search engine ads being used in Bitcoin wallet attacks, fraudsters are still using Bing ads to trick Blockchain users into visiting phishing sites — but this time, the ads are using some crude social engineering ploys.

Searching for "blockchain" on bing.com currently displays the following pair of phishing ads at the top of the search results:

"Other ads are all phishing site" – click this one!
(Page requested at 12:15 BST, 2nd July 2014)

The first ad begs the user to "click this one" and warns that all other ads are phishing sites, but clicking on the ad actually sends the victim to a Blockchain phishing site, where he is prompted to enter his identifier and password. This phishing site is hosted in a subdirectory on a compromised website, which belongs to a web development outsourcing company in India.

Similarly, the second phishing ad warns that the other one is a phishing site; however, the fraudster behind this ad has made a mistake. When a victim clicks on this ad, it will try to send him to blockchain.lnfo (.LNFO). This link won't work because the .lnfo top-level domain does not exist, and probably never will, because as the fraudster has so perfectly demonstrated, it could easily be confused with .info.

As we saw in previous attacks, the green display URLs shown in these ads are carefully chosen by the fraudster to look similar to the real Blockchain website, which uses the blockchain.info domain. Neither of the display URLs accurately reflect the actual location reached after clicking on the ads. Also, the blue link text on the second ad uses an i-acute character in place of the "i" in Blockchain, presumably to make it harder to detect misuse of the Blockchain brand.

The fact that these phishing ads are trying to discredit each other suggests that there are multiple Bitcoin fraudsters competing for click-through traffic on sites which display Bing ads. These phishing ads also appear on other search engines which use the Yahoo Bing ad network, such as Yahoo and DuckDuckGo.

A phishing ad displayed on the privacy-conscious DuckDuckGo search engine.

Steam phishing attacks exploiting look-alike domain names

An ongoing series of phishing attacks against the Steam gaming community is making effective use of look-alike domains to trick users into surrendering their usernames and passwords. The fraudsters behind these attacks then attempt to bypass Steam's two-factor authentication with a malicious executable that is deceptively named SteamGuard.exe.

One of the many look-alike domains involved in the attacks against steamcommunity.com

Victims are being targeted through Steam's own chat client, giving fraudsters the opportunity to spear phish accounts which are known to contain valuable tradable items. Since the inception of Steam Trading, it has become easier to monetize stolen accounts by selling the victim's virtual items to other Steam users.

Fraudsters are using Steam's own chat client to lure victims to phishing sites.
These sites use deceptive domain names, designed to look similar to the real steamcommunity.com.

If a targeted Steam user is persuaded to click on one of these links, he will be taken to a fake Steam profile. The following example shows another of these fake profiles on a similar look-alike domain. Profiles used in these attacks may appear to offer rare or unusual tradable items, and the high level and displayed XP score lends some degree of trustworthiness to potential trades.

The fake profile offers some attractive items up for trade.

To further entice the victim into trading with the fraudster, the fake profile also includes fabricated feedback which enhances the fraudster's reputation as a fast and reliable trader.

However, the fraudster is not intending to trade any items with his victim — he instead wants to gain access to the victim's account, and then steal the victim's own tradable items. When the victim clicks on the "Add Friend" button, he will be presented with a spoofed login form on the look-alike domain that requests his Steam username and password:

The stolen username and password will not be of much use to the fraudster if the victim has enabled Steam Guard. This two-factor authentication mechanism is enabled by default if the victim has a verified email address and has restarted Steam at least twice since verifying the address. If Steam Guard is enabled, the fraudster will be unable to access his victim's Steam account without entering an access code which is emailed only to the victim.

Bypassing Steam's two-factor authentication (Steam Guard)

Older Steam phishing sites simply asked the victim for their access code, but this approach is no longer suitable for trade fraudsters: there is now a time-delay before the trading feature can be used from a new device, which gives the victim an opportunity to recover his compromised account before any items can be traded by the fraudster.

Steam phishing sites consequently evolved to ask their victims to upload a special ssfn file. This file is located in the victim's Steam folder and acts as an authentication key, so that after providing a valid access code, the user does not have to keep on requesting and entering a new access code every time they launch Steam. If this file is copied to the fraudster's computer, he will be able to bypass the two-factor authentication mechanism and gain access to the victim's account.

The Steam phishing sites used in these latest attacks have evolved further still. Rather than tricking the victim into uploading the ssfn file, the phishing sites now display the following dialog box which prompts the victim to install a "special tool":

Unsurprisingly, this special tool is actually malware designed to find and upload the victim's ssfn file to the fraudster. The SteamGuard.exe file used in this particular attack is hosted on Google Drive, and submits the victim's ssfn file to a hard-coded URL on the phishing site it was originally downloaded from.

After the fraudster has been furnished with the victim's username, password and ssfn file, he will be able to login to the account and begin trading immediately.

Constant stream of look-alike domains

Since the start of May, more than a hundred look-alike domains have been registered specifically for the purpose of Steam phishing. More than a third of these phishing sites have been hosted in Russia, and many of the domains have also been registered to individuals with Russian addresses and email addresses at yandex.ru, a free webmail service.

Some of the 100+ look-alike domain names that have been registered for Steam phishing since May.

Most of the domains used in these attacks have been registered under the .com top-level domain. One notable counterexample is steamcommunity.cm, which uses the country code top-level domain for Cameroon. As well as being used in spear phishing attacks via Steam's chat client, it is likely that this particular phishing site could also have also received typo-traffic from Steam users.

More generally, the .cm ccTLD offers tremendous typosquatting opportunities against any corresponding .com domain. The domain's operators received criticism in the past when it wildcarded the entire .cm domain. It no longer does this, but there is evidently nothing stopping fraudsters from registering a .com domain's corresponding .cm domain anyway.

Using an "unusual hat" as a lure to visit the steamcommunity.cm phishing site.

Monetizing stolen Steam accounts

Albrecht Neumann, a mathematics student in Germany, is an active Steam trader who has reported some of these phishing attacks to Netcraft. He suspects the fraudsters are automatically searching trading portals for people who are offering to sell expensive items, and are then sending messages to those users via Steam: Each time he "bumps" a thread in which he is offering expensive items, he gets up to five new friend requests.

Neumann told Netcraft that keys and earbuds are a primary target for trade fraudsters, as these items serve as a relatively stable currency in the Steam economy, and are easy to turn into real money. Earbuds are cosmetic items which can be worn by a player's in-game character, and were given away to Mac OS X users who played Team Fortress 2 during a limited time period in 2010; but now they can only be obtained through trading. Some users stockpile these items in the hope that their value might increase and earn them a profit further down the line. Such items are valuable by virtue of their rarity, and can often be sold for $30-$40 each, making some accounts worth thousands.

All of the domain names used in these attacks were very similar to the real steamcommunity.com domain. Netcraft's Fraud Detection service helps brand owners pre-emptively identify these types of fraudulent domain registrations. Some of the domains were registered months before the attacks actually took place, which would have allowed plenty of time to get them shut down before they were misused. Domain registrars are in a position to nip this in the bud even earlier — they can use Netcraft's Domain Registration Risk service to prevent their customers from registering domain names which are deceptively similar to well known phishing targets.

Deceptive search engine ads used in Bitcoin wallet attacks

Fraudsters are exploiting loopholes in the presentation of ads by major search engines in order to lure victims to phishing sites. Searching for "blockchain", the name of a popular Bitcoin wallet provider, caused deceptive ads to be displayed at the top of search results pages from Google, Bing, Yahoo, and DuckDuckGo. In contrast to the traditional approach of sending emails indiscriminately, links to phishing sites in search engine ads may be much more convincing, especially when the domain they are impersonating is displayed as the destination.

With more than 1.7 million wallets, Blockchain.info is the most popular online Bitcoin wallet. Blockchain's My Wallet service allows users to send and receive payments in Bitcoins. When signing up, users are reminded that they must remember their passwords, as forgotten passwords cannot be recovered and will result in the loss of all Bitcoins stored in the wallet. These passwords are exactly what the fraudsters are after.

Phishing ads in Bing's search engine results. Screenshot taken on 19 June 2014 at 10:16 BST.

The above screenshot shows the results of searching for "blockchain" on Bing. The first link on the page is an ad, supposedly for the official Blockchain wallet service at Blockchain.info. However, clicking on this link actually takes victims to a phishing site under blockchaino.info (note the additional 'o' character).

Bing! There go your coins.

The phishing site at blockchaino.info immediately prompts a victim to enter his identifier and password, whereas the real Blockchain website only prompts for the user's identifier. Blockchain's security recommendations make it clear that the real Blockchain.info will never ask you for your password: "We NEVER need it and we NEVER want it". As soon as the fraudster has tricked the victim into giving up the required information, they "sweep the funds away".

This type of attack is likely to be extremely effective, as the ad displays the same domain name as the site it is targeting, and it is the first link to appear in the search engine results page. Some users may not realise that it is an ad, and instead believe that it is the top organic result. Showing the wrong display URL (green text) is forbidden by most ad networks' policies; however, the fraudsters have evidently managed to bypass these restrictions. Without strict enforcement, the ability to specify the displayed destination leaves such advertising open to fraud.

However, strict enforcement of destination URLs may alienate a search engine's customers — advertisers may use third-party services to manage their advertising and track clicks. These customers will rely on being able to display the final URL despite redirecting via a third-party service before reaching the target site. The use of redirects makes enforcement of any display policy difficult, as there is no guarantee that the target of the redirect will remain constant after the ad has been approved, or that the redirects presented to the search engine are the same as those presented to end users.

Another phishing site advertising at the top of Bing.

Other Bing ads directed victims to different Blockchain phishing sites, all of which used deceptive hostnames such as blockchain-info.itconflux.com, blockchain.info.pl and bllockchain.info.pl, but did not use the display domain of the site they were impersonating, blockchain.info.

It's not just Bing's search engine that has been affected by this phishing campaign. The search ads displayed at the top of Bing search results can appear anywhere on the Yahoo Bing Network. This means that the same fraudulent ads also appear when a victim searches for Blockchain on Yahoo.com. Similar phishing ads are also displayed on the DuckDuckGo search engine, which syndicates its sponsored links from the same network.

The same phishing ads appear on a Yahoo search for "blockchain".

And it is not just the Yahoo Bing ad network which is being exploited by phishers — search giant Google displayed the following phishing ad on its search results pages:

This Google phishing ad directed victims to blockchain-info.itconflux.com.

However, it's not necessarily game over if a victim's password has been stolen. If a Blockchain user has chosen to enable two-factor authentication via SMS, Yubikey or Google Authenticator, the fraudster will be unable to access the wallet at a later date unless he also has access to the victim's physical two factor authentication device (e.g. phone or Yubikey).

All of the sites involved in these attacks against Blockchain were blocked in Netcraft's phishing site feed, which allows third-party developers to integrate anti-phishing services into their products. Some of the domain names used in these attacks were very similar to the real blockchain.info domain. Netcraft's Fraud Detection service helps brand owners pre-emptively identify these types of fraudulent domain registrations, giving an opportunity to take action against the registrants, possibly before the attacks have even started.

Criminals launch mass phishing attacks against online dating sites

Criminals are running massive dedicated phishing campaigns against online dating sites, marking an interesting – but not unusual – shift in focus from the traditional phishing targets such as banks and other financial institutions. The most recent attack used a single compromised website to host hundreds of fraudulent PHP scripts, most of which were designed to steal usernames and passwords from users of the most popular dating sites.

The online dating sites targeted by the latest attack include match.com, Christian Mingle, POF (PlentyOfFish), eHarmony, Chemistry.com, SeniorPeopleMeet, Zoosk, Lavalife, amongst others. Only eight of the 862 fraudulent scripts on the server targeted banks.

It is likely that the criminals who steal accounts on these sites will go on to use them to commit online dating fraud — many dating sites only allow messages to be exchanged with other users after a subscription fee has been paid; by compromising existing paid accounts, the fraudsters can reduce their traceability by avoiding the need to make payments.

Part of one of the fraudulent scripts

Online dating fraud is often orchestrated by criminal gangs who use fake profiles to trick victims into developing long distance relationships. Once the fraudsters have gathered enough sympathy and trust from a victim, they will exploit this by claiming they need money to pay for travel costs, or to afford medical treatment for a family member. After the money has been stolen, the criminals will make up further reasons why they need more money. In some cases, the fraudsters blackmail their victim into sending money - if the victim has sent any explicit photos or videos to the criminals, they may threaten to send them to the victim's friends and family.

The amount of money involved in these scams can be considerable. In 2011, a woman in Britain was tricked into sending more than $59,000 to a pair of fraudsters who pretended to have inherited millions of dollars from a military friend in Nigeria. The fraudsters - who were actually a mother and daughter in America - managed to net more than a million dollars before being jailed in 2013.

While many online dating sites take measures to identify fake profiles, phishing for genuine established accounts gives fraudsters the edge. If a legitimate profile has been in active use for several months without cause for concern, then compromising this profile will allow the fraudster to benefit not just from the plausible appearance of the profile, but also take over several ongoing conversations. The real owner of the hijacked account will have already done the hard bit by establishing dialogues with other members on the site, possibly gaining enough trust to allow the fraudsters to strike immediately with success.

The latest attacks make use of a phishing kit which contains hundreds of PHP scripts, configured to send stolen credentials to more than 300 distinct email addresses. More than half of these addresses used the yahoo.com domain, while gmail.com was the next most common choice. Although most of the fraudster's scripts target online dating sites, some of them are also designed to steal credentials from users of these webmail platforms. Email accounts are often shut down after the provider notices they have been used for fraudulent purposes, so ensuring a fresh supply of compromised accounts gives fraudsters the opportunity to send even more phishing emails before the accounts get closed.

The phishing kit contains over 300 PHP scripts, most of which target online dating sites.

An attacker would typically deploy the phishing kit by uploading a zip file to a compromised web server and unzipping the tree of contents into a writable directory. Similar kits uploaded over the past few months have used various file names, such as moving.zip, send.zip, orokionline.zip, amioroki.zip and samoroki.zip. Each script within these kits is very similar in terms of functionality — they simply collate a set of POST parameters into the body of an email message, and then send it to two or more email addresses. The subject of the email is modified to describe what type of credentials are in the email (e.g. "MATCH ID & PASSWORD"), and after the emails have been sent, the victim is redirected to an appropriate URL on the target website, such as http://www.match.com/login/login.aspx?lid=2.

Each compromised server which hosts these scripts acts merely as a "dropsite" in the fraudsters' phishing campaigns. Rather than displaying any phishing content, the server simply accepts values that have been submitted from elsewhere, such as a form hosted on another website or within a phishing email. The victim is then immediately redirected to the legitimate website, most likely without realising that his credentials have just been transmitted to a different website.

Some of the scripts are also designed to steal credentials from Photobucket users, possibly so the fraudsters can host photos and other images to further their scams. It is not unusual for fraudsters to encourage their victims to migrate to instant messaging software or even text messages instead of continuing to chat on a dating site, which could be monitored to prevent such fraud.

National Crime Agency “urgent alert” site knocked offline

With only two weeks until the recently seized Gameover Zeus botnet is likely to be functioning again, the UK's National Crime Agency has published urgent advice on how to protect computers against the Gameover Zeus and CryptoLocker trojans.

Unfortunately, the page hosting this urgent advice is proving rather troublesome to view:

GetSafeOnline, Offline

When it can be viewed, the NCA's advice page at www.getsafeonline.org/nca/ outlines the threat and lists a set of tools which can be used to check for the presence of malware. The page also notes that the NCA "cannot over-stress the importance of taking these steps immediately" and "You must follow the advice on this page straight away".

With expectations of high traffic and the need for users to act immediately, it is surprising that this important information was not hosted on a platform which was capable of handling the load. Last night's tweet by @GetSafeOnline suggests that the performance issues are being caused by lots of traffic; there are no indications of an attack against the site.

Reverse DNS lookups for the www.getsafeonline.org hostname resolve to 170-203-253-62.static.virginm.net,
and the final hop in a traceroute is spc1-barn6-0-0-cust460.asfd.broadband.ntl.com

The FBI believes the Gameover Zeus trojan is responsible for more than one million computer infections, resulting in financial losses in the hundreds of millions of dollars. A Russian man believed to be involved in these attacks has been added to the FBI's Cyber's Most Wanted list.

The NCA announced the urgent alert on Facebook yesterday, prompting a stream of comments about the site not working

Since referring to the NCA's advice page in an article yesterday, the BBC's Dave Lee has mirrored the content on evernote so others can see it.

Ask.fm users being redirected to malware sites

Malicious adverts displayed on the Ask.fm website have been automatically redirecting users to malware sites, where they are prompted to install unwanted or malicious software under the pretense of Java and Flash Player updates.

This particular advert is benign and serves only as an example of the banner's placement

Ask.fm is a popular social network which allows its users to receive and answer anonymous questions, but both registered users and anonymous question askers are being put at risk by some of the adverts it displays: Merely viewing a user's profile on Ask.fm caused some users to be redirected to the following page, which claimed that an outdated Java plugin had been detected (even when Java had been disabled).

Rather than downloading a Java update, victims will instead end up installing a program which several anti-virus vendors identify as DomaIQ. This is an advertising platform used by adware and other malicious programs to display unwanted pop-up ads within Internet Explorer, Firefox and Google Chrome.

The rogue advert responsible for performing the redirection was initially served through ADTECH GmbH, which is a wholly-owned subsidiary of AOL. However, the trail does not end there – the framed content served by ADTECH subsequently requested several pages from AppNexus servers at ib.adnxs.com and ams1.ib.adnxs.com, before one of these pages initiated a request to a Java servlet on exchange.admailtiser.com. Finally, this servlet page caused the parent frame to be redirected from Ask.fm to the page on www.updriong.com, essentially taking the browser to a different website without requiring any user interaction.

After returning to the Ask.fm website, another rogue advert immediately redirected the browser to a fake Adobe Flash update site. Again, no user interaction was required – the chain of requests initiated by the third party advert automatically redirected the user's browser to the fake site hosted in Sweden.

In this case, the rogue advert on http://ask.fm/account/wall was again initially served by ADTECH, but the framed content made its next request to a Yahoo ad server (ads.yahoo.com), which in turn made a request to ad.copa-media.com, which itself made a request for content hosted on an AppNexus server at ams1.ib.adnxs.com.

Finally, a request to another AppNexus server at ib.adnxs.com resulted in the user's browser being redirected to the fake Adobe Flash update site at download.adoocobo.us. The setup.exe file is served from a domain which is known for propagating malware.

Mobile browsers have also been targeted by similar attacks on Ask.fm. The example below shows an Ask.fm webpage displaying an intrusive and unsolicited alert dialog which originates from a Yahoo ad server. If the user clicks OK, he will be taken to a site which falsely claims that his phone has severe battery issues.

Within a few minutes, another advert on Ask.fm attempted to download an Android app directly from a website in France as soon as the user clicked OK. The makers of the genuine Mobogenie Market app recommend that it should only be downloaded from reliable sources such as Google Play, mobogenie.com and other partner networks (although it does not specify who these are).

Incidentally, despite encouraging its users not to reveal their passwords to anyone, the login form on http://ask.fm transmits a user's password over an unencrypted HTTP connection:

Most high profile websites only ever transmit passwords over encrypted HTTPS connections, and many sites also ensure that the entire duration of a browser session remains encrypted, i.e. not just the login process. Sending plain text passwords over an unencrypted connection makes them vulnerable to eavesdropping, giving a correctly-positioned attacker the opportunity to gain unauthorised access to Ask.fm user accounts.