ESET researchers have discovered new DanaBot campaigns targeting a number of European countries.
Recently, we have spotted a surge in activity of DanaBot, a stealthy banking Trojan discovered earlier this year. The malware, first observed in campaigns targeting Australia and later Poland, has apparently expanded further, with campaigns popping up in Italy, Germany, Austria, and as of September 2018, Ukraine.
What is DanaBot?
DanaBot is a modular banking Trojan, first analyzed by Proofpoint in May 2018 after being discovered in malicious email campaigns targeting users in Australia. The Trojan is written in Delphi, has a multi-stage and multi-component architecture, with most of its functionality implemented by plug-ins. At the time of the discovery, the malware was said to have been under active development.
Just two weeks after the widely reported initial campaigns in Australia, DanaBot was detected in a campaign aimed at Poland. According to our research, the campaign targeting Poland is still ongoing and is the largest and most active campaign to date. To compromise their victims, the attackers behind the Poland-targeted campaign use emails posing as invoices from various companies, as seen in Figure 1. The campaign makes use of a combination of PowerShell and VBS scripts widely known as Brushaloader.
At the beginning of September, ESET researchers discovered several smaller campaigns targeting banks in Italy, Germany and Austria, using the same distribution method as observed in the Polish campaign. Further to this development, on September 8, 2018, ESET discovered a new DanaBot campaign targeting Ukrainian users. The software and websites targeted in these new campaigns are listed at the end of this article.
Figure 2 shows a spike in the DanaBot detection rate at the turn of August and again in September 2018, as seen in our telemetry data.
Given its modular architecture, DanaBot relies on plug-ins for most of its functionality.
The following plug-ins have previously been mentioned as a part of the Australia-targeted campaigns of May 2018:
- VNC plug-in – establishes a connection to a victim’s computer and remotely controls it
- Sniffer plug-in – injects malicious scripts into a victim’s browser, usually while visiting internet banking sites
- Stealer plug-in – harvests passwords from a wide variety of applications (browsers, FTP clients, VPN clients, chat and email programs, poker programs etc.)
- TOR plug-in – installs a TOR proxy and enables access to .onion web sites
According to our research, the attackers have introduced several changes to the DanaBot plug-ins since the previously reported campaigns.
In August 2018, the attackers started using the TOR plug-in for updating the C&C server list from y7zmcwurl6nphcve.onion. While this plug-in could potentially be used to create a covert communication channel between the attacker and a victim, we have no evidence of such a use to date.
In addition to that, the attackers have extended the Stealer plug-in range with a 64-bit version compiled on August 25, 2018, expanding the list of software potentially targeted by DanaBot.
Finally, in the beginning of September 2018, an RDP plug-in was added to DanaBot. It is based on the open-source project RDPWrap that provides Remote Desktop Protocol connections to Windows machines that normally do not support it.
There could be several reasons why the DanaBot developers added another plug-in that enables remote access besides the VNC plug-in: First, the RDP protocol is less likely to be blocked by firewalls. Second, RDPWrap allows several users to use the same machine concurrently, enabling attackers to perform reconnaissance operations while the unsuspecting victim is still using the machine.
Our findings show that DanaBot is still in active use and development, most recently testing out “new ground” in European countries. The new features introduced in these latest campaigns indicate the attackers behind DanaBot continue to make use of the malware’s modular architecture to increase their reach and success rate.
ESET systems detect and block all DanaBot components and plug-ins under detection names listed in the IoCs section. The software and domains targeted in these recent campaigns is listed in the following sections of this blog post.
This research was carried out by Tomáš Procházka and Michal Kolář.
Software targeted in all European campaigns
Software targeted in Ukrainian campaign
On September 8, 2018, DanaBot started targeting the following corporate banking software and remote access tools:
Note that wildcard characters are used in the configuration, so this list only contains portals which can be reliably identified.
Targeted Italian domains
Targeted German domains
Targeted Austrian domains
Targeted Ukrainian domains
Domains added on September 14, 2018:
Domains added on September 17, 2018:
- MDaemon Webmail
Targeted cryptocurrency wallets
Example configuration from campaigns targeting Poland, Italy, Germany and Austria
Indicators of Compromise (IoCs)
Servers used by DanaBot
Note that “Active” stands for serving malicious content as of September 20, 2018.
Note that new builds of the main components are released every ~15 minutes, so hashes may not be the latest available.
|Infection vector in Europe||782ADCF9EF6E479DEB31FCBD37918C5F74CE3CAE||VBS/TrojanDownloader.Agent.PYC|
|Infection vector in Ukraine||79F1408BC9F1F2AB43FA633C9EA8EA00BA8D15E8||JS/TrojanDropper.Agent.NPQ|
|Main module (x86)||EA3651668F5D14A2F5CECC0071CEB85AD775872C||Win32/Spy.Danabot.F|
|Main module (x64)||47DC9803B9F6D58CF06BDB49139C7CEE037655FE||Win64/Spy.Danabot.C|