The U.S. government today unsealed criminal charges against 16 individuals accused of operating and selling DanaBot, a prolific strain of information-stealing malware that has been sold on Russian cybercrime forums since 2018. The FBI says a newer version of DanaBot was used for espionage, and that many of the defendants exposed their real-life identities after accidentally infecting their own systems with the malware.

DanaBot’s features, as promoted on its support site. Image: welivesecurity.com.

Initially spotted in May 2018 by researchers at the email security firm Proofpoint, DanaBot is a malware-as-a-service platform that specializes in credential theft and banking fraud.

Today, the U.S. Department of Justice unsealed a criminal complaint and indictment from 2022, which said the FBI identified at least 40 affiliates who were paying between $3,000 and $4,000 a month for access to the information stealer platform.

The government says the malware infected more than 300,000 systems globally, causing estimated losses of more than $50 million. The ringleaders of the DanaBot conspiracy are named as Aleksandr Stepanov, 39, a.k.a. “JimmBee,” and Artem Aleksandrovich Kalinkin, 34, a.k.a. “Onix”, both of Novosibirsk, Russia. Kalinkin is an IT engineer for the Russian state-owned energy giant Gazprom. His Facebook profile name is “Maffiozi.”

According to the FBI, there were at least two major versions of DanaBot; the first was sold between 2018 and June 2020, when the malware stopped being offered on Russian cybercrime forums. The government alleges that the second version of DanaBot — emerging in January 2021 — was provided to co-conspirators for use in targeting military, diplomatic and non-governmental organization computers in several countries, including the United States, Belarus, the United Kingdom, Germany, and Russia.

“Unindicted co-conspirators would use the Espionage Variant to compromise computers around the world and steal sensitive diplomatic communications, credentials, and other data from these targeted victims,” reads a grand jury indictment dated Sept. 20, 2022. “This stolen data included financial transactions by diplomatic staff, correspondence concerning day-to-day diplomatic activity, as well as summaries of a particular country’s interactions with the United States.”

The indictment says the FBI in 2022 seized servers used by the DanaBot authors to control their malware, as well as the servers that stored stolen victim data. The government said the server data also show numerous instances in which the DanaBot defendants infected their own PCs, resulting in their credential data being uploaded to stolen data repositories that were seized by the feds.

“In some cases, such self-infections appeared to be deliberately done in order to test, analyze, or improve the malware,” the criminal complaint reads. “In other cases, the infections seemed to be inadvertent – one of the hazards of committing cybercrime is that criminals will sometimes infect themselves with their own malware by mistake.”

Image: welivesecurity.com

A statement from the DOJ says that as part of today’s operation, agents with the Defense Criminal Investigative Service (DCIS) seized the DanaBot control servers, including dozens of virtual servers hosted in the United States. The government says it is now working with industry partners to notify DanaBot victims and help remediate infections. The statement credits a number of security firms with providing assistance to the government, including ESET, Flashpoint, Google, Intel 471, Lumen, PayPal, Proofpoint, Team CYMRU, and ZScaler.

It’s not unheard of for financially-oriented malicious software to be repurposed for espionage. A variant of the ZeuS Trojan, which was used in countless online banking attacks against companies in the United States and Europe between 2007 and at least 2015, was for a time diverted to espionage tasks by its author.

As detailed in this 2015 story, the author of the ZeuS trojan created a custom version of the malware to serve purely as a spying machine, which scoured infected systems in Ukraine for specific keywords in emails and documents that would likely only be found in classified documents.

The public charging of the 16 DanaBot defendants comes a day after Microsoft joined a slew of tech companies in disrupting the IT infrastructure for another malware-as-a-service offering — Lumma Stealer, which is likewise offered to affiliates under tiered subscription prices ranging from $250 to $1,000 per month. Separately, Microsoft filed a civil lawsuit to seize control over 2,300 domain names used by Lumma Stealer and its affiliates.

Further reading:

Danabot: Analyzing a Fallen Empire

ZScaler blog: DanaBot Launches DDoS Attack Against the Ukrainian Ministry of Defense

Flashpoint: Operation Endgame DanaBot Malware

Team CYMRU: Inside DanaBot’s Infrastructure: In Support of Operation Endgame II

March 2022 criminal complaint v. Artem Aleksandrovich Kalinkin

September 2022 grand jury indictment naming the 16 defendants

Microsoft today issued more than 50 security updates for its various Windows operating systems, including fixes for a whopping six zero-day vulnerabilities that are already seeing active exploitation.

Two of the zero-day flaws include CVE-2025-24991 and CVE-2025-24993, both vulnerabilities in NTFS, the default file system for Windows and Windows Server. Both require the attacker to trick a target into mounting a malicious virtual hard disk. CVE-2025-24993 would lead to the possibility of local code execution, while CVE-2025-24991 could cause NTFS to disclose portions of memory.

Microsoft credits researchers at ESET with reporting the zero-day bug labeled CVE-2025-24983, an elevation of privilege vulnerability in older versions of Windows. ESET said the exploit was deployed via the PipeMagic backdoor, capable of exfiltrating data and enabling remote access to the machine.

ESET’s Filip Jurčacko said the exploit in the wild targets only older versions of Windows OS: Windows 8.1 and Server 2012 R2. Although still used by millions, security support for these products ended more than a year ago, and mainstream support ended years ago. However, ESET notes the vulnerability itself also is present in newer Windows OS versions, including Windows 10 build 1809 and the still-supported Windows Server 2016.

Rapid7’s lead software engineer Adam Barnett said Windows 11 and Server 2019 onwards are not listed as receiving patches, so are presumably not vulnerable.

“It’s not clear why newer Windows products dodged this particular bullet,” Barnett wrote. “The Windows 32 subsystem is still presumably alive and well, since there is no apparent mention of its demise on the Windows client OS deprecated features list.”

The zero-day flaw CVE-2025-24984 is another NTFS weakness that can be exploited by inserting a malicious USB drive into a Windows computer. Barnett said Microsoft’s advisory for this bug doesn’t quite join the dots, but successful exploitation appears to mean that portions of heap memory could be improperly dumped into a log file, which could then be combed through by an attacker hungry for privileged information.

“A relatively low CVSSv3 base score of 4.6 reflects the practical difficulties of real-world exploitation, but a motivated attacker can sometimes achieve extraordinary results starting from the smallest of toeholds, and Microsoft does rate this vulnerability as important on its own proprietary severity ranking scale,” Barnett said.

Another zero-day fixed this month — CVE-2025-24985 — could allow attackers to install malicious code. As with the NTFS bugs, this one requires that the user mount a malicious virtual hard drive.

The final zero-day this month is CVE-2025-26633, a weakness in the Microsoft Management Console, a component of Windows that gives system administrators a way to configure and monitor the system. Exploiting this flaw requires the target to open a malicious file.

This month’s bundle of patch love from Redmond also addresses six other vulnerabilities Microsoft has rated “critical,” meaning that malware or malcontents could exploit them to seize control over vulnerable PCs with no help from users.

Barnett observed that this is now the sixth consecutive month where Microsoft has published zero-day vulnerabilities on Patch Tuesday without evaluating any of them as critical severity at time of publication.

The SANS Internet Storm Center has a useful list of all the Microsoft patches released today, indexed by severity. Windows enterprise administrators would do well to keep an eye on askwoody.com, which often has the scoop on any patches causing problems. Please consider backing up your data before updating, and leave a comment below if you experience any issues applying this month’s updates.