APT28 Rollercoaster: The Lowdown on Hijacked LoJack
Recently, the ASERT team at Arbor Networks, published a report on an old version of the Absolute Software product, Absolute LoJack for laptops, being illicitly modified by suspected APT28 actors. The LoJack implant, previously known as Computrace and brought into the spotlight in 2014 at Black Hat USA because it was enabled on some brand new laptops, is an anti-theft technology used in modern laptops to allow remote tracing, data deletion, and system lockdown.
Based on information from a number of reports, ASERT estimates with moderate confidence that the APT28 group, also known as Fancy Bear, has maliciously modified and deployed Absolute LoJack samples to support its own campaigns against government and defense-related contractors. (See the advice from Absolute Software regarding these modified samples.) As sophisticated implants often reveal non-trivial dynamic behaviors, we began an investigation process to analyze this threat in more detail.
A New Sample
From the IOCs in the ASERT report, we hunted through our knowledge base for additional samples using the search query below:
code_hash: '21B04C7DF33277B9927D0D3E3ADC545D' AND user_agent: 'Mozilla/4.0 (compatible; MSIE 6.0;)' AND NOT domain: 'search.namequery.com'
The code hash search term allowed us to query for all LoJack implants. We filtered on user agent while removing the resolved domain used by all legitimate implants. The search uncovered a new and previously unmentioned sample, below (see Figure 1 for the analysis overview):
Compilation time: 2008-04-01 19:35:07
C&C server: webstp[.]com
This new sample was detected for the first time in the second half of 2017, the sample relies on a previously unknown C&C server: the webstp[.]com domain originally resolved to the IP address 185.94.191[.]65, but was later sinkholed at sinkhole.tigersecurity.pro via 91.134.203[.]113 and later 54.36.134[.]247.
Our investigation started by focusing on that specific domain and IP association. While we had no reputation information related to the IP 185.94.191[.]65, whois historical data showed that webstp[.]com had been registered on August 11, 2017 with the hosting company ititch[.]com (Figure 2).
In their own words:
“IT Itch is different. We’re all about helping people, businesses and activist groups keep their digital identity anonymous, their online data private and their websites always online. We’re doing this by actively ignoring and impeding digital data requests and take-down notices, and we’re pretty good at it – we have a 100% non-compliance rate. We’re also helping domain name owners and website operators understand more about data privacy protection, and offering products and services designed to keep your identity secret, such as anonymous web hosting and private domain registration.”
Whether intentionally or not, this desire to support internet freedoms has attracted cyberthreat actors because of the operational anonymity and bulletproof infrastructure.
The Fallback Revelation
During our investigation, we decided to verify whether we could detect other hijacked LoJack samples being used in the wild. As the traffic from hijacked agents is otherwise indistinguishable from legitimate agents, we deployed a network signature to monitor HTTP traffic with the same distinct User-Agent header, but connecting to other (non-legitimate) domains. Unfortunately, this approach quickly proved to be prone to false positives; in particular, in a small number of legitimate LoJack interactions, the contacted host of the HTTP request was a plain IP address instead of a domain name (see Figure 3).
The fact that a legitimate sample was including this fallback mechanism led us to wonder whether the malicious binary was doing the same. As Figure 4 shows, that was indeed the case: it turns out Computrace samples embed both a XORed IP address as well as a XORed domain. The XORed IP address is used as a backup communication channel when domain callout fails (the logic can be seen in Figure 5).
We also checked all other hijacked LoJack implants, and in all cases, the binary included a fallback IP, meaning that in all cases the implant would have been able to connect to the C&C regardless of whether the domain had been sinkholed or blacklisted. Only in two cases, the fallback IP address did not match the address pointed to by the domain. Table 1 shows detailed network IOCs for all known hijacked LoJack samples.
|Sample SHA1||Domain||Original resolving IP||Fallback IP|
Table 1: Hijacked LoJack samples and their C&C infrastructure (including the fallback IP). In bold the sample we uncovered.
We can assert with high confidence that this specific hijacked Absolute LoJack for laptops sample appears to be related to the campaign recently unveiled by Arbor Networks. Our reasoning follows:
- The domain webstp[.]com is associated to an Absolute LoJack agent utilizing the exact same compile time of other hijacked LoJack samples, thus matching the same criteria used to cluster the original artifacts.
- The domain sysanalyticweb[.]com and webstp[.]com share the same registrar, ititch[.]com, a company claiming to provide bulletproof hosting, and used in other APT28 campaigns.
- The domain in the registrant email address for webstp[.]com is centrum[.]cz, which appears frequently in other registrant email addresses of domains linked to previous APT28 campaigns associated with ititch[.]com.
- The Absolute LoJack for laptops agent connecting to webstp[.]com has been seen in the wild during the same time frame of all other samples.
In this blog post, we further analyzed the C&C infrastructure used by the samples of Absolute LoJack for laptops illicitly modified by APT28. We unveiled a new sample submitted from organizations with a consistent victimology to other LoJack targets and domains that are part of the C&C infrastructure. We also discovered that all Absolute LoJack for laptops samples had a fallback mechanism to increase their robustness against sinkholes. This infrastructure used in our new sample is linked to pro-European Union companies and/or ex-Soviet Union states. We will continue to publish new IOCs in this blog for the LoJack campaign as future submissions appear.
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