Mofang (模仿, Mófa ̌ng, to imitate) is a threat actor that almost certainly operates out of China and is probably government-affiliated. It is highly likely that Mofang’s targets are selected based on involvement with investments, or technological advances that could be perceived as a threat to the Chinese sphere of influence. This is most clearly the case in a campaign focusing on government and critical infrastructure of Myanmar that is described in this report. Chances are about even, though, that Mofang is a relevant threat actor to any organization that invests in Myanmar or is otherwise politically involved. In addition to the campaign in Myanmar, Mofang has been observed to attack targets across multiple sectors (government, military, critical infrastructure and the automotive and weapon industries) in multiple countries.

The following countries have, in the above named sectors, been affected, although Fox-IT suspects there to be more: India, Germany, United States, Canada, Singapore, South Korea.

Despite its diverse set of targets Mofang is probably one group. This is based on the fact that its tools (ShimRat and ShimRatReporter) are not widely used, and that campaigns are not usually observed in parallel. Technically, the group uses distinct tools that date back to at least February 2012: ShimRat and ShimRatReporter. The mofang group does not use exploits to infect targets, they rely on social engineering and their attacks are carried out in three stages:

1. Compromise for reconnaissance, aiming to extract key information about the target infrastructure.
2. Faux infrastructure setup, designed to avoid attracting attention.
3. The main compromise, to carry out actions on the objective.

The name ShimRat is based on how its persistence is build up. It uses the so-called shims in Windows to become persistent. Shims are simply hot patching processes on the fly, to ensure backward compatibility of software on the Microsoft Windows platform.

As far as known, the only exploits the Mofang group uses are privilege elevation exploits built into their own malware. The vulnerabilities that were being exploited were already known about at the time of use. The full report contains contextual as well as technical information about the group and its activities. These can be used, for example, for threat assessments, compromise assessments, incident response and forensics activities.

Download ‘Mofang – a politically motivated information stealing adversary’

Since early this morning (7th of June 2016, around 08:30 AM) the Fox-IT Security Operations Center started detecting a large amount of phishing e-mails containing a malicious Word document. This e-mail campaign appears to be targeting the Netherlands, using Dutch text in both the e-mail and Word document. The content of the e-mail:

Geachte Firstname Lastname,
Role, Company

Wij schrijven u in verband met de factuur met nummer 014321463.
De nota staat open sinds 9-jun-16. Het openstaande bedrag is 2,487.50 Euro. 
Vriendelijk verzoeken wij u het openstaande bedrag te betalen.

Betaling graag zo spoedig mogelijk.

Met vriendelijke groet,

A.E. De Kuiper,
BEEREJAN HOLDING BV.
Faisantenstraat 53 Hilversum 1211 PT
Tel. +31180647000
Fax. +31294484970

The first name, last name, role and company name are all values that are taken from the LinkedIn page of the receiver of the phishing mail, giving the e-mail a very personalized look.

The subject of the e-mail contain the company name, with a semi-random invoice related subject. Some examples:

• Company : De nota is nog niet betaald
• Company – De nota is onbetaald gebleven
• Company – Uw laatste factuur wacht op betaling

At this point Fox-IT cannot directly link this phishing campaign to the recent LinkedIn database leak.

The e-mail contains a Word document with a Macro.
The name of the document is also based on personal information of the receiver:

• Company-Firstname-Lastname.doc

The content of the Word document appears to be scrambled, this is an attempt to trick the user into running the embedded Macro, in order to view the document.

The Macro retrieves a binary from the following (likely compromised) website:

• ledpronto.com/app/office.bin (sha256: c1e21a06a1fa1de2998392668b6910ca2be0d5d9ecc39bd3e3a2a3ae7623400d)

The Fox-IT InTELL team has identified the retrieved malware as the Zeus Panda banking malware. Zeus Panda, in this case, always connects to the following domain & IP using SSL:

• skorianial.com / 107.171.187.182

Zeus Panda is a type of banking malware based on Zeus source code, more information can be found here: https://www.proofpoint.com/us/threat-insight/post/panda-banker-new-banking-trojan-hits-the-market

The following SSL certificate is used by the Panda Zeus Command and Control server:

If you’ve opened the Word attachment and enabled the Macro, consider scanning your system with various anti-virus solutions.

Fox-IT has encountered various ways in which ransomware is being spread and activated. Many infections happen by sending spam e-mails and luring the receiver in opening the infected attachment. Another method is impersonating a well-known company in a spam e-mail stating an invoice or track&trace information is ready for download. By following the link provided in the e-mail, the receiver can download the file which contains the malware from a convincing looking website. Distributing ransomware through malvertising, an exploit kit being served on an advertisement network, is also a common way for criminals to infect systems.

In the past few months, Fox-IT’s incident response team, FoxCERT, was involved in several investigations where a different technique surfaced: activating ransomware from a compromised remote desktop server.

Getting access

Before we get to why this might be lucrative for the criminals, how do they get access in the first place? RDP, or Remote Desktop Protocol, is a propriety protocol developed by Microsoft to provide remote access to a system over the network. This can be the local network, but also the Internet. When a user successfully connects to a system running remote desktop services (formerly known as terminal services) over RDP, the user is presented with a graphical interface similar to that when working on the system itself. This is widely used by system administrators for managing various systems in the organization, by users working with thin clients, or for working remotely. Attackers mostly tend to abuse remote desktop services for lateral movement after getting foothold in the network. In this case however, RDP is their point of entry into the network.

Entries in the log files show the attackers got access to the servers by brute forcing usernames and passwords on remote desktop servers that are accessible from the internet. Day in, day out, failed login attempts are recorded coming from hundreds of unique IP-addresses trying hundreds of unique usernames. Connecting remote desktop servers directly to the internet is not recommended and brute forcing remote desktop services is nothing new. But without the proper controls in place to prevent or at least detect and respond to successful compromises, brute force RDP attacks are still relevant. And now with a ransomware twist as well.

Image 1: Example network with compromised RDP server and attacker deploying ransomware.

The impact

After brute forcing credentials to gain access to a remote desktop server, the attackers can do whatever the user account has permissions to on the server and network. So how could an attacker capitalize on this? Underground markets exist where RDP credentials can be sold for an easy cash-out for the attacker. A more creative attacker could attempt all kinds of privileged escalation techniques to ultimately become domain administrator (if not already), but most of the times this is not even necessary as the compromised user account might have access to all kinds of network shares with sensitive data. For example Personally identifiable information (PII) or Intellectual property (IP) which in its turn can be exfiltrated and sold on underground markets. The compromised user account and system could be added to a botnet, used as proxy server, or used for sending out spam e-mail messages. Plenty of possibilities, including taking the company data hostage by executing ransomware.

Depending on the segmentation and segregation of the network, the impact of ransomware being executed from a workstation in a client LAN might be limited to the network segments and file shares the workstation and affected user account can reach. From a server though, an attacker might be able to find and reach other servers and encrypt more critical company data to increase the impact.

The power lies in the amount of time the attackers can spend on reconnaissance if no proper detection controls are in place. For example, the attackers have time to analyze how and when back-ups are created of critical company data before executing the ransomware. This helps to make sure the back-ups are useless in restoring the encrypted data which in its turn increases the chances of a company actually paying the ransom. In the cases Fox-IT was involved in investigating the breaches, the attackers spend weeks actively exploring the network by scanning and lateral movement. As soon as the ransomware was activated, no fixed ransom was demanded but negotiation by e-mail was required. As the attackers have a lot of knowledge of the compromised network and company, their position in the negotiation is stronger than when infection took place through a drive-by download or infected e-mail attachment. The demanded ransom reflects this and could be significantly higher.

Image 2: Example ransomware wallpaper.

Prevention, detection, response

Connecting Remote Desktop Services to the Internet is a risk. Services like that, which are not essential, should be disabled. If remote access is necessary, user accounts with remote access should have hard to guess passwords and preferably a second factor for authentication (2FA) or second step in verification (2SV). To prevent eaves dropping on the remote connection, a strong encryption channel is recommended. Brute force attacks on remote desktop servers and ransomware infections can be prevented. Fox-IT can help to improve your company’s security posture and prevent attacks, for example by an architecture review, security audit or training.

If prevention fails, swift detection will reduce the impact. With verbose logging securely stored and analyzed, accompanied by 24/7 network and end point monitoring an ongoing breach or malware infection will be detected and remediated. The Cyber Threat Management platform can assist in detecting and preventing attacks. And if business continuity and reputation are at stake, our emergency response team is available 24/7.

Wouter Jansen, Senior Forensic IT Expert at Fox-IT

On Sunday April 10th the Fox-IT Security Operations Center (SOC) started to see an increase of exploit kit related incidents. The incidents originated from a large malvertising campaign hitting the Netherlands. The list of affected websites spreads across most of the popular Dutch websites. In total we’ve now seen at least 288 websites being affected. To give an impression of the impact, the list of affected websites includes:

• nu.nl
• marktplaats.nl
• sbs6.nl
• rtlnieuws.nl
• rtlz.nl
• startpagina.nl
• buienradar.nl
• kieskeurig.nl
• veronicamagazine.nl
• iculture.nl
• panorama.nl

Note: Malvertising is caused by malicious content providers in the advertisement ecosystem, and not caused by the affected websites themselves (f.e those listed above).

We’ve been in contact with the affected advertisement provider who responded quickly to the incident and has filtered the listed IOCs in their advertisement platform. They will be tracking down the affected content provider as this issue has not been fully resolved, it has simply been filtered for now. More information on malvertising can be found here: [ Malvertising: Not all Java from java.com is legitimate ].

Details of the exploit kit redirect

The malvertising is occurring through an advertisement platform which is actively used on the above mentioned websites. From the websites, external scripts are loaded which in turn redirect further towards the exploit kit. We’ve observed the Angler Exploit Kit being active on these redirects during this campaign. We have not seen any successful infections at our customer yet.

One of the redirects towards the Angler exploit kit as observed by our monitoring platform:

Indicators of Compromise (IOCs)

The following two domains have been observed to redirect the users from the affected websites towards the exploit kits. Blocking these two domains will aid in stopping the redirects for now:

• traffic-systems.biz (188.138.69.136)
• medtronic.pw (188.138.68.191)

Since Monday the 21st of March the Fox-IT Security Operations Center (SOC) has been observing malicious redirects towards the Angler exploit kit coming from the security certification provider known as the EC-COUNCIL. As of writing this blog article on the Thursday the 24th of March the redirect is still present on the EC-COUNCIL iClass website for CEH certification located at iclass[dot]eccouncil[dot]org. We have reached out and notified the EC-COUNCIL but no corrective action has been taken yet.

Update 25-4-2016: EC-COUNCIL put out a publication regarding the malicious redirect. They’ve cleaned up and removed the malicious redirect, the publication was made on their Facebook page and linked to on their Twitter account.

Exploit kit details: Angler exploit kit

We first observed the redirect on Monday around 3pm GMT but we suspect it might have been there for a longer period of time. The redirect occurs only when specific conditions are met, these conditions are:

• The visitor has to have Microsoft Internet Explorer as a browser (or at least the user-agent has to represent Internet Explorer)
• The visitor comes from a search engine like Google or Bing
• The visitor’s IP address is not blacklisted or belonging to a blocked geolocation. The inject avoids certain countries (possibly tied to a bad ‘ROI’ for the criminals running the ransomware that is being dropped)

Once a visitor meets all these requirements a redirect is embedded at the bottom of the page as seen in this screenshot:

Through this embedding the client is redirected a couple of times to avoid/frustrate/stop manual analysis and some automated systems. Once the user has jumped through all the redirects he/she ends up on the Angler exploit kit landing page from which the browser, flashplayer plugin or silverlight plugin will be exploited. The Angler exploit kit first starts the ‘Bedep’ loader on an exploited victim machine which will download the final payload.

The way the redirect occurs on the EC-COUNCIL website is through PHP code on the webserver which is injecting the redirect into the webpage. A vulnerability in the EC-COUNCIL website is most likely exploited as it runs the very popular WordPress CMS which has been a target through vulnerable plug-ins for years.

Payload details: TeslaCrypt

This specific campaign instance of the Angler exploit kit drops ‘TeslaCrypt’ on the exploited victim’s machine. TeslaCrypt is a piece of ransomware which takes a victim’s files hostage with the use of encryption. Once the victim’s files have been successfully encrypted a ransom note is presented to instruct the victim on ways to recover files:

TeslaCrypt requires the victim to pay around 1.5 BTC to get their files back; this equals to approximately 622$ at the current conversion rate.

Indicators of Compromise (IOCs)

Bedep C&C servers:

• 89.163.240.118 / kjnoa9sdi3mrlsdnfi[.]com
• 85.25.41.95 / moregoodstafsforus[.]com
• 89.163.241.90 / jimmymorisonguitars[.]com
• 162.244.32.121 / bookersmartest[.]xyz

TeslaCrypt C&C servers:

• 50.87.127.96 / mkis[.]org
• 213.186.33.104 / tradinbow[.]com