As I covered in last week’s newsletter, law enforcement agencies from around the globe have been touting recent botnet disruptions affecting the likes of some of the largest threat actors and malware families.  

Operation Endgame, which Europol touted as the “largest ever operation against botnets,” targeted malware droppers including the IcedID banking trojan, Trickbot ransomware, the Smokeloader malware loader, and more.  

A separate disruption campaign targeted a botnet called “911 S5,” which the FBI said was used to “commit cyber attacks, large-scale fraud, child exploitation, harassment, bomb threats, and export violations.” 

But with these types of announcements, I think there can be confusion about what a botnet disruption means, exactly. As we’ve written about before in the case of the LockBit ransomware, botnet and server disruptions can certainly cause headaches for threat actors, but usually are not a complete shutdown of their operations, forcing them to go offline forever.  

I’m not saying that Operation Endgame and the 911 S5 disruption aren’t huge wins for defenders, but I do think it’s important to separate botnets from the malware and threat actors themselves.  

For the uninitiated, a botnet is a network of computers or other internet-connected devices that are infected by malware and controlled by a single threat actor or group. Larger botnets are often used to send spam emails in large volumes or carry out distributed denial-of-service attacks by using a mountain of IP addresses to send traffic to a specific target all in a short period. Smaller botnets might be used in targeted network intrusions, or financially motivated botnet controllers might be looking to steal money from targets. 

When law enforcement agencies remove devices from these botnets, it does disrupt actors’ abilities to carry out these actions, but it’s not necessarily the end of the final payload these actors usually use, such as ransomware.  

When discussing this topic in relation to the Volt Typhoon APT, Kendall McKay from our threat intelligence team told me in the latest episode of Talos Takes that botnets should be viewed as separate entity from a malware family or APT. In the case of Volt Typhoon, the FBI said earlier this year it had disrupted the Chinese APT’s botnet, though McKay said “we’re not sure yet” if this has had any tangible effects on their operations. 

With past major botnet disruptions like Emotet and other Trickbot efforts, she also said that “eventually, those threats re-emerge, and the infected devices re-propagate [because] they have worm-like capabilities.” 

So, the next time you see headlines about a botnet disruption, know that yes, this is good news, but it’s also not time to start thinking the affected malware is gone forever.  

The one big thing 

This week, Cisco Talos disclosed a new malware campaign called “Operation Celestial Force” running since at least 2018. It is still active today, employing the use of GravityRAT, an Android-based malware, along with a Windows-based malware loader we track as “HeavyLift.” Talos attributes this operation with high confidence to a Pakistani nexus of threat actors we’re calling “Cosmic Leopard,” focused on espionage and surveillance of their targets.  

Why do I care? 

While this operation has been active for at least the past six years, Talos has observed a general uptick in the threat landscape in recent years, with respect to the use of mobile malware for espionage to target high-value targets, including the use of commercial spyware. There are two ways that this attacker commonly targets users to be on the lookout for: One is spearphishing emails that look like they’re referencing legitimate government-related documents and issues, and the other is social media-based phishing. Always be vigilant about anyone reaching out to you via direct messages on platforms like Twitter and LinkedIn.  

So now what? 

Adversaries like Cosmic Leopard may use low-sophistication techniques such as social engineering and spear phishing, but will aggressively target potential victims with various TTPs. Therefore, organizations must remain vigilant against such motivated adversaries conducting targeted attacks by educating users on proper cyber hygiene and implementing defense in depth models to protect against such attacks across various attack surfaces. 

Top security headlines of the week 

Microsoft announced changes to its Recall AI service after privacy advocates and security engineers warned about the potential privacy dangers of such a feature. The Recall tool in Windows 11 takes continuous screenshots of users’ activity which can then be queried by the user to do things like locate files or remember the last thing they were working on. However, all that data collected by Recall is stored locally on the device, potentially opening the door to data theft if a machine were to be compromised. Now, Recall will be opt-in only, meaning it’ll be turned off by default for users when it launches in an update to Windows 11. The feature will also be tied to the Windows Hello authentication protocol, meaning anyone who wants to look at their timeline needs to log in with face or fingerprint ID, or a unique PIN. After Recall’s announcement, security researcher Kevin Beaumont discovered that the AI-powered feature stored data in a database in plain text. That could have made it easy for threat actors to create tools to extract the database and its contents. Now, Microsoft has also made it so that these screenshots and the search index database are encrypted, and are only decrypted if the user authenticates. (The Verge, CNET) 

A data breach affecting cloud storage provider Snowflake has the potential to be one of the largest security events ever if the alleged number of affected users is accurate. Security researchers helping to address the attack targeting Snowflake said this week that financially motivated cybercriminals have stolen “a significant volume of data” from hundreds of customers. As many as 165 companies that use Snowflake could be affected, which is notable because Snowflake is generally used to store massive volumes of data on its servers. Breaches affecting Ticketmaster, Santander bank and Lending Tree have already been linked to the Snowflake incident. Incident responders working on the breach wrote this week that the attackers used stolen credentials to access customers’ Snowflake instances and steal valuable data. The activity dates back to at least April 14. Reporters at online news outlet TechCrunch also found that hundreds of Snowflake customer credentials were available on the dark web, after malware infected Snowflake staffers’ computers. The list poses an ongoing risk to any Snowflake users who had not changed their passwords as of the first disclosure of this breach or are not protected by multi-factor authentication. (TechCrunch, Wired) 

Recovery of a cyber attack affecting several large hospitals in London could take several months to resolve, according to an official with the U.K.’s National Health Service. The affected hospitals and general practitioners’ offices serve a combined 2 million patients. A recent cyber attack targeting a private firm called Synnovis that analyzes blood tests has forced these offices to reschedule appointments and cancel crucial surgeries. “It is unclear how long it will take for the services to get back to normal, but it is likely to take many months,” the NHS official told The Guardian newspaper. Britain also had to put out a call for volunteers to donate type O blood as soon as possible, as the attack has made it more difficult for health care facilities to match patients’ blood types at the same frequency as usual. Type O blood is generally known to be safe for all patients and is commonly used in major surgeries. (BBC, The Guardian) 

Can’t get enough Talos? 

Upcoming events where you can find Talos 

Cisco Connect U.K. (June 25)

London, England

In a fireside chat, Cisco Talos experts Martin Lee and Hazel Burton discuss the most prominent cybersecurity threat trends of the near future, how these are likely to impact UK organizations in the coming years, and what steps we need to take to keep safe.

BlackHat USA (Aug. 3 – 8) 

Las Vegas, Nevada 

Defcon (Aug. 8 – 11) 

Las Vegas, Nevada 

BSides Krakow (Sept. 14)  

Krakow, Poland 

Most prevalent malware files from Talos telemetry over the past week 

SHA 256: 2d1a07754e76c65d324ab8e538fa74e5d5eb587acb260f9e56afbcf4f4848be5 
MD5: d3ee270a07df8e87246305187d471f68 
Typical Filename: iptray.exe 
Claimed Product: Cisco AMP 
Detection Name: Generic.XMRIGMiner.A.A13F9FCC

SHA 256: 9b2ebc5d554b33cb661f979db5b9f99d4a2f967639d73653f667370800ee105e 
MD5: ecbfdbb42cb98a597ef81abea193ac8f 
Typical Filename: N/A 
Claimed Product: MAPIToolkitConsole.exe 
Detection Name: Gen:Variant.Barys.460270 

SHA 256: 9be2103d3418d266de57143c2164b31c27dfa73c22e42137f3fe63a21f793202 
MD5: e4acf0e303e9f1371f029e013f902262 
Typical Filename: FileZilla_3.67.0_win64_sponsored2-setup.exe 
Claimed Product: FileZilla 
Detection Name: W32.Application.27hg.1201 

SHA 256: a024a18e27707738adcd7b5a740c5a93534b4b8c9d3b947f6d85740af19d17d0 
MD5: b4440eea7367c3fb04a89225df4022a6 
Typical Filename: Pdfixers.exe 
Claimed Product: Pdfixers 
Detection Name: W32.Superfluss:PUPgenPUP.27gq.1201 

SHA 256: 0e2263d4f239a5c39960ffa6b6b688faa7fc3075e130fe0d4599d5b95ef20647 
MD5: bbcf7a68f4164a9f5f5cb2d9f30d9790 
Typical Filename: bbcf7a68f4164a9f5f5cb2d9f30d9790.vir 
Claimed Product: N/A 
Detection Name: Win.Dropper.Scar::1201