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One certificate was generated locally on what appeared to be a HP-UX box , and another was generated on 8569985.securefastserver.com with an email address root@8569985.securefastserver.com , as seen here for their nethostnet.com domain .
This certificate configuration is ignored by the malware .
Sofacy , one of the most active APT we monitor , continues to spearphish their way into targets , reportedly widely phishes for credentials , and infrequently participates in server side activity ( including host compromise with BeEF deployment , for example ) .
KSN visibility and detections suggests a shift from their early 2017 high volume NATO spearphish targeting towards the middle east and Central Asia , and finally moving their focus further east into late 2017 .
Their operational security is good .
Their campaigns appear to have broken out into subsets of activity and malware involving GAMEFISH , Zebrocy , and SPLM , to name a few .
Their evolving and modified SPLM / CHOPSTICK / XAgent code is a long-standing part of Sofacy activity , however much of it is changing .
We ’ll cover more recent 2018 change in their targeting and the malware itself at SAS 2018 .
A journey to Zebrocy land .
The Sednit group – also known as APT28 , Fancy Bear , Sofacy or STRONTIUM – has been operating since at least 2004 and has made headlines frequently in past years .
Recently , we unveiled the existence of a UEFI rootkit , called LoJax , which we attribute to the Sednit group .
This is a first for an APT group , and shows Sednit has access to very sophisticated tools to conduct its espionage operations .
Three years ago , the Sednit group unleashed new components targeting victims in various countries in the Middle East and Central Asia .
Since then , the number and diversity of components has increased drastically .
ESET researchers and colleagues from other companies have documented these components ; however , in this article we will focus on what ’s beyond the compromise , what the operators do once a victim system is running a Zebrocy Delphi backdoor .
At the end of August 2018 , the Sednit group launched a spearphishing email campaign where it distributed shortened URLs that delivered the first stage of Zebrocy components .
In the past , Sednit used a similar technique for credential phishing .
However , it is unusual for the group to use this technique to deliver one of its malware components directly .
Previously , it had used exploits to deliver and execute the first stage malware , while in this campaign the group relied entirely on social engineering to lure victims into running the first part of the chain .
The screenshot in Figure 1 shows Bitly statistics for the shortened URL used in this campaign .
While ESET telemetry data indicates that this URL was delivered by spearphishing emails , we don’t have a sample of such an email .
The shortened URL leads the victim to an IP-address-based URL , where the archived payload is located .
Unfortunately , without the email message , we don’t know if there are any instructions for the user , if there is any further social engineering , or if it relies solely on the victim ’s curiosity .
The archive contains two files ; the first is an executable file , while the second is a decoy PDF document .
Note there is a typo in the executable ’s filename ; Once the binary is executed , a password prompt dialog box opens .
The result of the password validation will always be wrong , but after the apparent validation attempt , the decoy PDF document is opened .
That document appears to be empty , but the downloader , which is written in Delphi , continues running in the background .
The IP address is also used in the URL hardcoded into the first binary downloader .
The Stage-1 downloader will download and execute a new downloader , written in C++ , not so different from other Zebrocy downloaders .
Once again this downloader is as straightforward as the Zebrocy gang ’s other downloaders .
It creates an ID and it downloads a new , interesting backdoor , ( this time ) written in Delphi .
As we explained in our most recent blogpost about Zebrocy , the configuration of the backdoor is stored in in the resource section and is split into four different hex-encoded , encrypted blobs .
These blobs contain the different parts of the configuration .
Once the backdoor sends basic information about its newly compromised system , the operators take control of the backdoor and start to send commands right away .
Hence , the time between the victim running the downloader and the operators ’ first commands is only a few minutes .
In this section we describe in more detail the commands performed manually by the operators through their Delphi backdoor .
The commands available are located in one of the configuration blobs mentioned earlier .
The number of supported commands has increased over time , with the latest version of the backdoor having more than thirty .
As we did not identify a pattern in the order which the commands are invoked , we believe the operators are executing them manually .
The first set of commands gathers information about the victim ’s computer and environment :Commands Arguments SCREENSHOT None SYS_INFO None GET_NETWORK None SCAN_ALL None .
The commands above are commonly executed when the operators first connect to a newly activated backdoor .
They don’t have any arguments , and they are quite self-explanatory .
Other commands commonly seen executed shortly after these backdoors are activated .
Those who already have read our previous articles about Zebrocy will notice that more or less the same kind of information is sent , over and over again by previous stages .
This information is requested within a few minutes of initial compromise and the amount of data the operator will have to deal with is quite considerable .
In order to collect even more information , from time to time the Zebrocy operators upload and use dumpers on victims ’ machines .
The current dumpers have some similarities with those previously used by the group .
In this case , Yandex Browser , Chromium , 7Star Browser ( a Chromium-based browser ) , and CentBrowser are targeted , as well as versions of Microsoft Outlook from 1997 through 2016 .
These dumpers create log files indicating the presence or absence of potential databases to dump :Command Arguments DOWNLOAD_LIST C:\ProgramData\Office\MS\out.txt , C:\ProgramData\Office\MS\text.txt .
These dumpers are quickly removed once they have done their job .
Moreover , the backdoor contains a list of filenames related to credentials from software listed below ( database names ) :key3.db Firefox private keys ( now named key4.db ) cert8.db Firefox certificate database logins.json Firefox encrypted password database account.cfn The Bat ! ( email client ) account credentials wand.dat Opera password database .
The operators retrieve these files on the machine using the DOWNLOAD_LIST command .
This command can be used when the operators are aware of the presence of interesting files on the computer .
Finally , depending on how interesting the victim is , they malware operators may deploy another custom backdoor .
This backdoor is executed using the CMD_EXECUTE command .
There are some interesting facts here .
First , they use COM object hijacking to make the malware persistent on the system even though the custom backdoor is installed only for a few hours .
Second , the hex-encoded string is the C&C used by the custom backdoor while in the Delphi backdoor the C&C is embedded in the configuration .
Sofacy Group’s Parallel Attacks .
The Sofacy group remains a persistent global threat .
Unit 42 and others have shown in the first half of 2018 how this threat actor group continues to target multiple organizations throughout the world with a strong emphasis on government , diplomatic and other strategic organizations primarily in North America and Europe .
Following up our most recent Sofacy research in February and March of 2018 , we have found a new campaign that uses a lesser known tool widely attributed to the Sofacy group called Zebrocy .
Zebrocy is delivered primarily via phishing attacks that contain malicious Microsoft Office documents with macros as well as simple executable file attachments .
This third campaign is consistent with two previously reported attack campaigns in terms of targeting : the targets were government organizations dealing with foreign affairs .
In this case however the targets were in different geopolitical regions .
An interesting difference we found in this newest campaign was that the attacks using Zebrocy cast a far wider net within the target organization : the attackers sent phishing emails to a an exponentially larger number of individuals .
The targeted individuals did not follow any significant pattern , and the email addresses were found easily using web search engines .
This is a stark contrast with other attacks commonly associated with the Sofacy group where generally no more than a handful of victims are targeted within a single organization in a focus-fire style of attack .
In addition to the large number of Zebrocy attacks we discovered , we also observed instances of the Sofacy group leveraging the Dynamic Data Exchange ( DDE ) exploit technique previously documented by McAfee .
The instances we observed , however , used the DDE exploit to deliver different payloads than what was observed previously .
In one instance the DDE attack was used to deliver and install Zebrocy .
In another instance , the DDE attack was used to deliver an open-source penetration testing toolkit called Koadic .
The Sofacy group has leveraged open source or freely available tools and exploits in the past but this is the first time that Unit 42 has observed them leveraging the Koadic toolkit .
In our February report , we discovered the Sofacy group using Microsoft Office documents with malicious macros to deliver the SofacyCarberp payload to multiple government entities .
In that report , we documented our observation that the Sofacy group appeared to use conventional obfuscation techniques to mask their infrastructure attribution by using random registrant and service provider information for each of their attacks .
In particular , we noted that the Sofacy group deployed a webpage on each of the domains .
This is odd because attackers almost never set up an actual webpage on adversary C2 infrastructure .
Even stranger , each webpage contained the same content within the body .
Since that report , we continued our research into this oddity .
Using this artifact , we were able to pivot and discover another attack campaign using the DealersChoice exploit kit with similar victimology to what we saw in February .
Continuing to use this artifact , we discovered another domain with the same content body , supservermgr.com .
This domain was registered on December 20 , 2017 and within a few days was resolving to 92.222.136.105 , which belonged to a well-known VPS provider often used by the Sofacy group .
Unfortunately , at the time of collection , the C2 domain had been sinkholed by a third party .
Based on dynamic and static analysis of the malware sample associated with the supservermgr.com domain however , we were able to determine several unique artifacts which allowed us to expand our dataset and discover additional findings .
First , we determined the sample we collected , d697160aecf152a81a89a6b5a7d9e1b8b5e121724038c676157ac72f20364edc was attempting to communicate to its C2 at http://supservermgr.com/sys/upd/pageupd.php to retrieve a Zebrocy AutoIT downloader .
Because the domain had been sinkholed , this activity could not be completed .
Using AutoFocus , we pivoted from the user agent string to expand our data set to three additional Zebrocy samples using the exact same user agent .
This led us to additional infrastructure for Zebrocy at 185.25.51.198 and 185.25.50.93 .
At this point we had collected nearly thirty samples of Zebrocy in relation to the original sample and its associated C2 domain .
Additional pivoting based on artifacts unique to this malware family expanded our dataset to hundreds of samples used over the last several years .
Most of the additional samples were the Delphi and AutoIT variants as reported by ESET .
However , several of the collected samples were a C++ variant of the Zebrocy downloader tool .
In addition , we discovered evidence of a completely different payload in Koadic being delivered as well .
Also , we found the IP address 185.25.50.93 hosting C2 services for a Delphi backdoor that ESET ’s report states is the final stage payload for these attacks .
Please note this is not a comprehensive chart of all Zebrocy and Koadic samples we were able to collect .
Only samples mentioned or relevant to the relational analysis have been included .
From the 185.25.50.93 C2 IP , we discovered another hard-coded user agent being used by Zebrocy :Mozilla ( Windows NT 6.1 ; WOW64 ) WinHttp/1.6.3.8 ( WinHTTP/5.1 ) like Gecko .
We observed several samples of Zebrocy using this user agent targeting the foreign affairs ministry of a large Central Asian nation .
Pivoting off of this artifact provided us additional Zebrocy samples .
One sample in particular , cba5ab65a24be52214736bc1a5bc984953a9c15d0a3826d5b15e94036e5497df used yet another unique user agent string in combination with the previous user agent for its C2 : Mozilla v5.1 ( Windows NT 6.1 ; rv : 6.0.1 ) Gecko Firefox .