Calisto (aka Callisto, COLDRIVER) is suspected to be a Russian-nexus intrusion set active since at least April 2017. Although it was not publicly attributed to any Russian intelligence service, past Calisto operations showed objectives and victimology that align closely with Russian strategic interests.
Calisto mainly focuses on Western countries, especially the United States, and Eastern European countries. The group was observed carrying out phishing campaigns aiming at credential theft, targeting military and strategic research sectors such as NATO entities and a Ukraine-based defense contractor, as well as NGOs and think tanks. Additional victimology includes former ntelligence ofﬁcials, experts in Russian matters, and Russian citizens abroad.
While Security Service of Ukraine (SBU) publicly associated Calisto with Gamaredon Group, an intrusion set attributed to the Russian Federal Security Service (FSB) that focuses essentially on Ukraine operations since the beginning of the Russian invasion in February 2022, this link is not supported by other security companies or researchers. SEKOIA.IO conducted further technical investigations but did not ﬁnd any overlap between Calisto and Gamaredon activities.
Based on SEKOIA.IO EvilNgix trackers, we came across domains, known to us as aligning with past Calisto activities. Further investigations led to a larger infrastructure composed of more than 80 domains, including domains typosquatting entites.
As several of these domains were already known and resolving IP addresses already attributed to Calisto activities, SEKOIA.IO associates these domains to Calisto with high conﬁdence.
In past observed campaigns, Calisto operators sent malicious PDF attachments to their victims. The ﬁrst page of the PDF mimics an error in the PDF renderer engine, inciting the victim to open a link leading to a malicious web page. This webpage aims at gathering the victim’s credentials by using EvilGinx. Here are a few examples of PDF retrieved in this investigation:
The last pages of the documents contain blobs of spirals and text, as shown below. SEKOIA.IO analysts still don’t know why such gibberish is used as it appears useless as an anti-detection trick. However, the idea to put the phishing link in a PDF instead of in the email body prevents link analysis from email gateways and is a good tactic to remain undetected from an attacker point of view.
SEKOIA.IO conducted open-source research on the typosquatted domains, to identify targets. As we redact this paper, we found six private companies based in the US and Eastern Europe, and four Non-governmental organizations (NGOs), all involved in Ukraine support. SEKOIA.IO contacted the NGOs to get the phishing email or payload.
One of them shared the email exchange between the victim and the attacker using a
spoofed email from a “trusted source”, including the malicious PDF payload, a technique previously observed in Calisto campaigns. The email exchange shows that the attacker did not include the malicious payload in the ﬁrst email, but waited to get an answer to build a relationship and avoid suspicion before sending the payload to the victim. That Calisto social engineering technique was already observed by Microsoft.
Most of the targeted private organizations are involved in military equipment, military logistics or humanitarian support for Ukraine, including a US company that provides humanitarian logistics and possibly tactical equipment to Kiev. Other sectors include communication technologies and cybersecurity (medium conﬁdence) :
- UMO, Polish company, military equipment (high conﬁdence);
- Emcompass, Ukrainian company, military logistic (high conﬁdence);
- DTGruelle, US company, logistics (high conﬁdence);
- Global Ordnance, US company, military and tactical equipment (high conﬁdence);
- BotGuard, Estonian company, cybersecurity (medium conﬁdence);
- Blue Sky Network, US company, satellite communications (high conﬁdence).
Additional potential victims include NGOs and think tanks involved in conﬂict resolution and war crime investigation, including an organization also involved in the Syrian civil war crime investigation and previously targeted by an Indian hack-for-hire company in June 2020. Most of the NGOs and think tanks targeted are publicly supporting Ukraine.
- International Center on Nonviolent Conﬂict, US think tank promoting non-military strategies by civilian-based movements to defend human rights (high conﬁdence);
- Commission for International Justice and Accountability, Europe-based NGO, proof collection for human rights violation and war crime (high conﬁdence);
- Centre for Humanitarian Dialogue, Swiss-based NGO, mediation and diplomacy for conﬂict resolution (high conﬁdence);
- Foundation for support of reforms in Ukraine, Ukraine-based NGO, economic reforms promotion, likely involved in post-war reconstruction planning (medium conﬁdence).
SEKOIA.IO notes that the observed victimology through the investigation matches known Calisto victimology, namely strategic research, civil society and military equipment sectors, as well as entities and individuals involved in Russian matters.
Calisto targets non-directly related to Ukraine support
Among discovered Calisto malicious domains, three caught SEKOIA.IO analysts’ attention, mvd-redir[.]ru and dns-mvd[.]ru (high conﬁdence) that are highly likely typosquatting the Russian Ministry of Interior, and lk-nalog-gov[.]ru (low conﬁdence) the Russian Federal Taxation Service. Based on the fact that Calisto was observed targeting Russian individuals abroad, SEKOIA.IO assess it is plausible that Calisto conducts domestic surveillance as well. Another less plausible hypothesis would be a false-ﬂag maneuver to raise doubts on the infrastructure’s attribution.
SEKOIA.IO found another potential victim that matches Calisto known targeting. The domain
sangrail-share[.]com and sangrail-ltd[.]com are typosquatting Sangrail Inc., a private security
company, registered in the UK on 31 July 2019 by Ian Walter Baharie. That name was used as well to register AC21 , a British private intelligence company focused on African politics. Interestingly, that name showed up in a 17-years-old data leak exposing a list of several MI6 oﬃcers on cryptome.org, a website dedicated to information leaks. That observation matches Microsoft assessment on Calisto targeting former intelligence oﬃcers.
Despite the absence of technical evidence associating Calisto activities with a known Russian cyber offensive service, Sekoia.io assess that this intrusion set intelligence collection activities targeting parties involved in Ukraine support, especially those in the tactical equipment logistics, probably contribute to Russian efforts to disrupt Kiev supply-chain for military reinforcements.
Based on the targeting of Commission for International Justice and Accountability NGO, Sekoia.io assess that Calisto contributes to Russian intelligence collection about identiﬁed war crime-related evidence and/or international justice procedures, likely to anticipate and build counter narrative on future accusations.
To provide our customers with actionable intelligence, Sekoia.io analysts will continue to monitor state-sponsored advanced and persistent threats, including Calisto, as well as cybercrime related groups. We welcome any feedback and / or additional input to further contribute to understanding and countering Calisto threat.
IOCs & Technical Details
access-confirmation[.]com allow-access[.]com antibots-service[.]com apicomcloud[.]com as-mvd[.]ru attach-docs[.]com attach-update[.]com blueskynetwork-drive[.]com blueskynetwork-shared[.]com botguard-checker[.]com botguard-web[.]com challenge-identifier[.]com challenge-share[.]com checker-bot[.]com cija-docs[.]com cija-drive[.]com cloud-safety[.]online cloud-us[.]online default-dns[.]online disk-previewer[.]com dns-cache[.]online dns-challenge[.]com dns-cookie[.]com dns-mvd[.]ru docs-cache[.]online docs-collector[.]com docs-shared[.]online docs-storage-ltd[.]com docs-viewer[.]online docs-web[.]online document-guard[.]com document-sender[.]com drive-control[.]com drive-defender[.]com drive-global-ordnance[.]com drive-globalordnance[.]com drive-information[.]com drive-previewer[.]com drive-us[.]online dtgruelle-drive[.]com dtgruelle-us[.]com encompass-drive[.]com encompass-shared[.]com filter-bot[.]com global-ordnance-drive[.]com goweb-protect[.]com goweb-service[.]com guard-checker[.]com hd-centre-drive[.]com hd-docs-share[.]com hypertexttech[.]com hypertextttech[.]com land-of-service[.]com live-identifier[.]com mvd-cloud[.]ru mvd-redir[.]ru network-storage-ltd[.]com nonviolent-conflict-service[.]com nonviolent-conflict-storage[.]com online-word[.]com preview-docs[.]com preview-docs[.]online protectedshields-storage[.]com protection-web-app[.]com proxycrioisolation[.]com redir-document[.]com response-collector[.]com response-filter[.]com response-mvd[.]ru response-redir[.]com safe-proof[.]com sangrail-ltd[.]com sangrail-share[.]com selector-drafts[.]online share-drive-ua[.]com soaringeagle-drive[.]com storage-service[.]online threatcenterofreaserch[.]com threatcenterofresearch[.]com transfer-dns[.]com transfer-record[.]com umo-drive[.]com umopl-drive[.]com umopl[.]com webview-service[.]com
External references :
 https://www.ac21.co.uk/, accessed December 5, 2024
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