Apr 16, 2024NewsroomEncryption / Network Security

The maintainers of the PuTTY Secure Shell (SSH) and Telnet client are alerting users of a critical vulnerability impacting versions from 0.68 through 0.80 that could be exploited to achieve full recovery of NIST P-521 (ecdsa-sha2-nistp521) private keys.

The flaw has been assigned the CVE identifier CVE-2024-31497, with the discovery credited to researchers Fabian Bäumer and Marcus Brinkmann of the Ruhr University Bochum.

“The effect of the vulnerability is to compromise the private key,” the PuTTY project said in an advisory.

“An attacker in possession of a few dozen signed messages and the public key has enough information to recover the private key, and then forge signatures as if they were from you, allowing them to (for instance) log in to any servers you use that key for.”

However, in order to obtain the signatures, an attacker will have to compromise the server for which the key is used to authenticate to.

In a message posted on the Open Source Software Security (oss-sec) mailing list, Bäumer described the flaw as stemming from the generation of biased ECDSA cryptographic nonces, which could enable the recovery of the private key.

“The first 9 bits of each ECDSA nonce are zero,” Bäumer explained. “This allows for full secret key recovery in roughly 60 signatures by using state-of-the-art techniques.”

“These signatures can either be harvested by a malicious server (man-in-the-middle attacks are not possible given that clients do not transmit their signature in the clear) or from any other source, e.g. signed git commits through forwarded agents.”

Besides impacting PuTTY, it also affects other products that incorporate a vulnerable version of the software –

• FileZilla (3.24.1 – 3.66.5)
• WinSCP (5.9.5 – 6.3.2)
• TortoiseGit (2.4.0.2 – 2.15.0)
• TortoiseSVN (1.10.0 – 1.14.6)

Following responsible disclosure, the issue has been addressed in PuTTY 0.81, FileZilla 3.67.0, WinSCP 6.3.3, and TortoiseGit 2.15.0.1. Users of TortoiseSVN are recommended to use Plink from the latest PuTTY 0.81 release when accessing an SVN repository via SSH until a patch becomes available.

Specifically, it has been resolved by switching to the RFC 6979 technique for all DSA and ECDSA key types, abandoning its earlier method of deriving the nonce using a deterministic approach that, while avoiding the need for a source of high-quality randomness, was susceptible to biased nonces when using P-521.

On top of that, ECDSA NIST-P521 keys used with any of the vulnerable components should be considered compromised and consequently revoked by removing them from authorized_keys files files and their equivalents in other SSH servers.

Apr 13, 2024Newsroom

Threat actors have been exploiting the newly disclosed zero-day flaw in Palo Alto Networks PAN-OS software dating back to March 26, 2024, nearly three weeks before it came to light yesterday.

The network security company’s Unit 42 division is tracking the activity under the name Operation MidnightEclipse, attributing it as the work of a single threat actor of unknown provenance.

The security vulnerability, tracked as CVE-2024-3400 (CVSS score: 10.0), is a command injection flaw that enables unauthenticated attackers to execute arbitrary code with root privileges on the firewall.

It’s worth noting that the issue is applicable only to PAN-OS 10.2, PAN-OS 11.0, and PAN-OS 11.1 firewall configurations that have GlobalProtect gateway and device telemetry enabled.

Operation MidnightEclipse entails the exploitation of the flaw to create a cron job that runs every minute to fetch commands hosted on an external server (“172.233.228[.]93/policy” or “172.233.228[.]93/patch”), which are then executed using the bash shell.

The attackers are said to have manually managed an access control list (ACL) for the command-and-control (C2) server to ensure that it can only be accessed from the device communicating with it.

While the exact nature of the command is unknown, it’s suspected that the URL serves as a delivery vehicle for a Python-based backdoor on the firewall that Volexity – which discovered in-the-wild exploitation of CVE-2024-3400 on April 10, 2024 – is tracking as UPSTYLE and is hosted on a different server (“144.172.79[.]92” and “nhdata.s3-us-west-2.amazonaws[.]com”).

The Python file is designed to write and launch another Python script (“system.pth”), which subsequently decodes and runs the embedded backdoor component that’s responsible for executing the threat actor’s commands in a file called “sslvpn_ngx_error.log.” The results of the operation are written to a separate file named “bootstrap.min.css.”

The most interesting aspect of the attack chain is that both the files used to extract the commands and write the results are legitimate files associated with the firewall –

• /var/log/pan/sslvpn_ngx_error.log
• /var/appweb/sslvpndocs/global-protect/portal/css/bootstrap.min.css

As for how the commands are written to the web server error log, the threat actor forges specially crafted network requests to a non-existent web page containing a specific pattern. The backdoor then parses the log file and searches for the line matching the same regular expression (“img\[([a-zA-Z0-9+/=]+)\]”) to decode and run the command within it.

“The script will then create another thread that runs a function called restore,” Unit 42 said. “The restore function takes the original content of the bootstrap.min.css file, as well as the original access and modified times, sleeps for 15 seconds and writes the original contents back to the file and sets the access and modified times to their originals.”

The main goal appears to be to avoid leaving traces of the command outputs, necessitating that the results are exfiltrated within 15 seconds before the file is overwritten.

Volexity, in its own analysis, said it observed the threat actor remotely exploiting the firewall to create a reverse shell, download additional tooling, pivot into internal networks, and ultimately exfiltrate data. The exact scale of the campaign is presently unclear. The adversary has been assigned the moniker UTA0218 by the company.

“The tradecraft and speed employed by the attacker suggests a highly capable threat actor with a clear playbook of what to access to further their objectives,” the American cybersecurity firm said.

“UTA0218’s initial objectives were aimed at grabbing the domain backup DPAPI keys and targeting active directory credentials by obtaining the NTDS.DIT file. They further targeted user workstations to steal saved cookies and login data, along with the users’ DPAPI keys.”

Organizations are recommended to look for signs of lateral movement internally from their Palo Alto Networks GlobalProtect firewall device.

The development has also prompted the U.S. Cybersecurity and Infrastructure Security Agency (CISA) to add the flaw to its Known Exploited Vulnerabilities (KEV) catalog, requiring federal agencies to apply the patches by April 19 to mitigate potential threats. Palo Alto Networks is expected to release fixes for the flaw no later than April 14.

“Targeting edge devices remains a popular vector of attack for capable threat actors who have the time and resources to invest into researching new vulnerabilities,” Volexity said.

“It is highly likely UTA0218 is a state-backed threat actor based on the resources required to develop and exploit a vulnerability of this nature, the type of victims targeted by this actor, and the capabilities displayed to install the Python backdoor and further access victim networks.”

Apr 12, 2024NewsroomNetwork Security / Zero-Day

Palo Alto Networks is warning that a critical flaw impacting its PAN-OS software used in its GlobalProtect gateways is being exploited in the wild.

Tracked as CVE-2024-3400, the issue has a CVSS score of 10.0, indicating maximum severity.

“A command injection vulnerability in the GlobalProtect feature of Palo Alto Networks PAN-OS software for specific PAN-OS versions and distinct feature configurations may enable an unauthenticated attacker to execute arbitrary code with root privileges on the firewall,” the company said in an advisory published today.

The flaw impacts the following versions of PAN-OS, with fixes expected to be released on April 14, 2024 –

• PAN-OS < 11.1.2-h3
• PAN-OS < 11.0.4-h1
• PAN-OS < 10.2.9-h1

The company also said that the issue is applicable only to firewalls that have the configurations for both GlobalProtect gateway (Network > GlobalProtect > Gateways) and device telemetry (Device > Setup > Telemetry) enabled.

Cybersecurity firm Volexity has been credited with discovering and reporting the bug.

While there are no other technical details about the nature of the attacks, Palo Alto Networks acknowledged that it’s “aware of a limited number of attacks that leverage the exploitation of this vulnerability.”

In the interim, it’s recommending customers with a Threat Prevention subscription to enable Threat ID 95187 to secure against the threat.

The development comes as Chinese threat actors have increasingly relied on zero-day flaws impacting Barracuda Networks, Fortinet, Ivanti, and VMware to breach targets of interest and deploy covert backdoors for persistent access.

Apr 11, 2024NewsroomEndpoint Security / Ransomware

A threat actor tracked as TA547 has targeted dozens of German organizations with an information stealer called Rhadamanthys as part of an invoice-themed phishing campaign.

“This is the first time researchers observed TA547 use Rhadamanthys, an information stealer that is used by multiple cybercriminal threat actors,” Proofpoint said. “Additionally, the actor appeared to use a PowerShell script that researchers suspect was generated by a large language model (LLM).”

TA547 is a prolific, financially motivated threat actor that’s known to be active since at least November 2017, using email phishing lures to deliver a variety of Android and Windows malware such as ZLoader, Gootkit, DanaBot, Ursnif, and even Adhubllka ransomware.

In recent years, the group has evolved into an initial access broker (IAB) for ransomware attacks. It has also been observed employing geofencing tricks to restrict payloads to specific regions.

The email messages observed as part of the latest campaign impersonate the German company Metro AG and contain a password-protected ZIP file containing a ZIP archive that, when opened, initiates the execution of a remote PowerShell script to launch the Rhadamanthys stealer directly in memory.

Interestingly, the PowerShell script used to load Rhadamanthys includes “grammatically correct and hyper specific comments” for each instruction in the program, raising the possibility that it may have been generated (or rewritten) using an LLM.

The alternate hypothesis is that TA547 copied the script from another source that had used generative AI technology to create it.

“This campaign represents an example of some technique shifts from TA547 including the use of compressed LNKs and previously unobserved Rhadamanthys stealer,” Proofpoint said. “It also provides insight into how threat actors are leveraging likely LLM-generated content in malware campaigns.”

The development comes as phishing campaigns have also been banking on uncommon tactics to facilitate credential-harvesting attacks. In these emails, recipients are notified of a voice message and are directed to click on a link to access it.

The payload retrieved from the URL is heavily obfuscated HTML content that runs JavaScript code embedded within an SVG image when the page is rendered on the target system.

Present within the SVG data is “encrypted data containing a second stage page prompting the target to enter their credentials to access the voice message,” Binary Defense said, adding the page is encrypted using CryptoJS.

Other email-based attacks have paved the way for Agent Tesla, which has emerged as an attractive option for threat actors due to it “being an affordable malware service with multiple capabilities to exfiltrate and steal users’ data,” according to Cofense.

Social engineering campaigns have also taken the form of malicious ads served on search engines like Google that lure unsuspecting users into downloading bogus installers for popular software like PuTTY, FileZilla, and Room Planner to ultimately deploy Nitrogen and IDAT Loader.

The infection chain associated with IDAT Loader is noteworthy for the fact that the MSIX installer is used to launch a PowerShell script that, in turn, contacts a Telegram bot to fetch a second PowerShell script hosted on the bot.

This PowerShell script then acts as a conduit to deliver another PowerShell script that’s used to bypass Windows Antimalware Scan Interface (AMSI) protections as well as trigger the execution of the loader, which subsequently proceeds to load the SectopRAT trojan.

“Endpoints can be protected from malicious ads via group policies that restrict traffic coming from the main and lesser known ad networks,” Jérôme Segura, principal threat researcher at Malwarebytes, said.

Apr 03, 2024The Hacker NewsCybersecurity / Penetration Testing

Attack surface management (ASM) and vulnerability management (VM) are often confused, and while they overlap, they’re not the same. The main difference between attack surface management and vulnerability management is in their scope: vulnerability management checks a list of known assets, while attack surface management assumes you have unknown assets and so begins with discovery. Let’s look at both in more detail.

What is vulnerability management?

Vulnerability management is, at the simplest level, the use of automated tools to identify, prioritize and report on security issues and vulnerabilities in your digital infrastructure.

Vulnerability management uses automated scanners to run regular, scheduled scans on assets within a known IP range to detect established and new vulnerabilities, so you can apply patches, remove vulnerabilities or mitigate any potential risks. These vulnerabilities tend to use a risk score or scale – such as CVSS – and risk calculations.

Vulnerability scanners often have many thousands of automated checks at their disposal, and by probing and gathering information about your systems, they can identify security gaps which could be used by attackers to steal sensitive information, gain unauthorized access to your systems, or disrupt your business. Armed with this knowledge, you can protect your organization and prevent potential attacks.

A screenshot of the Intruder vulnerability management platform, which is designed to perform thousands of security checks, identifying vulnerabilities in web apps, APIs, cloud systems, and beyond.

What is the vulnerability management process?

1. Performing a vulnerability scan
2. Assessing your vulnerability risk
3. Prioritizing and fixing vulnerabilities
4. Monitoring continuously

What is attack surface management?

The main difference between vulnerability management and attack surface management is the scope. Attack surface management (ASM) includes asset discovery – helping you to find all your digital assets and services and then reducing or minimizing their exposure to prevent hackers from exploiting them.

With ASM, all known or unknown assets (on-premises, cloud, subsidiary, third-party, or partner environments) are detected from the attacker’s perspective from outside the organization. If you don’t know what you’ve got, how can you protect it?

Take the example of an admin interface like cPanel or a firewall administration page – these may be secure against all known current attacks today, but a vulnerability could be discovered tomorrow – when it becomes a significant risk. If you monitor and reduce your attack surface, regardless of vulnerabilities, you become harder to attack.

So, a significant part of attack surface management is reducing exposure to possible future vulnerabilities by removing unnecessary services and assets from the internet. But to do this, first you need to know what’s there.

What is the attack surface management process?

1. Discover and map all your digital assets
2. Ensure visibility and create a record of what exists
3. Run a vulnerability scan to identify any weaknesses
4. Automate so everyone who creates infrastructure can do so securely
5. ‍Continuously monitor as new infrastructure and services are spun up

Intruder’s attack surface management features help you to stay on top of changes in your environment, such as recently opened ports and services.

How does attack surface management differ from vulnerability management?

Vulnerability management is the process of identifying and prioritizing vulnerabilities in your IT infrastructure and applications. Attack surface management goes a step further by identifying and analyzing your attack surface – all the devices, entry points and exposed services that an attacker could potentially use to gain access to your systems or data.

Can you combine Attack Surface Management and Vulnerability Management?

While ASM and VM may have different scopes and objectives, they’re not mutually exclusive. Used in combination, they create a much more holistic, robust and comprehensive cyber security posture. By identifying your assets and vulnerabilities, you can prioritize your security efforts and allocate resources more effectively – which will help you reduce the likelihood of a successful attack and any potential impact.

How Intruder can help with ASM and VM

Ultimately, you want to leave no stone unturned when it comes to cyber security. Modern VM and ASM solutions like Intruder can detect vulnerabilities affecting your organization. It gives you greater visibility and control over your attack surface, monitors network changes and SSL/TLS certificate expiry dates, helps you stay on top of your cloud infrastructure, and allows you to pay only for active targets. Why not see for yourself with a free 14-day trial?

Mar 28, 2024NewsroomCyber Espionage / Malware

The Police of Finland (aka Poliisi) has formally accused a Chinese nation-state actor tracked as APT31 for orchestrating a cyber attack targeting the country’s Parliament in 2020.

The intrusion, per the authorities, is said to have occurred between fall 2020 and early 2021. The agency described the ongoing criminal probe as both demanding and time-consuming, involving extensive analysis of a “complex criminal infrastructure.”

The breach was first disclosed in December 2020, with the Finnish Security and Intelligence Service (Supo) describing it as a state-backed cyber espionage operation designed to penetrate the Parliament’s information systems.

“The police have previously informed that they are investigating the hacking group APT31’s connections with the incident,” Poliisi said. “These connections have now been confirmed by the investigation, and the police have also identified one suspect.”

APT31, also called Altaire, Bronze Vinewood, Judgement Panda, and Violet Typhoon (formerly Zirconium), is a Chinese state-backed group that has been active since at least 2010.

Earlier this week, the U.K. and the U.S. blamed the adversarial collective for engaging in a widespread cyber espionage campaign targeting businesses, government officials, dissidents, and politicians.

Seven operatives associated with the group have been charged in the U.S. for their involvement in the hacking spree. Two of them – Ni Gaobin and Zhao Guangzong – have been sanctioned by the two nations, alongside a company named Wuhan XRZ, which allegedly served as a cover for orchestrating cyber attacks against critical infrastructure.

“Guangzong is a Chinese national who has conducted numerous malicious cyber operations against U.S. victims as a contractor for Wuhan XRZ,” the U.S. Treasury said. “Ni Gaobin assisted Zhao Guangzong in many of his most high profile malicious cyber activities while Zhao Guangzong was a contractor at Wuhan XRZ.”

In July 2021, the U.S. and its allies implicated APT31 in a widespread campaign exploiting zero-day security flaws in Microsoft Exchange servers with the goal of likely “acquiring personally identifiable information and intellectual property.”

China, however, has hit back against the accusations that it’s behind the hacking campaign targeting the West. It has accused the Five Eyes (FVEY) alliance of spreading “disinformation about the threats posed by the so-called ‘Chinese hackers.'”

“We urge the U.S. and the U.K. to stop politicizing cybersecurity issues, stop smearing China and imposing unilateral sanctions on China, and stop cyberattacks against China,” China’s Foreign Ministry Spokesperson Lin Jian said. “China will take necessary measures to firmly safeguard its lawful rights and interests.”

Mar 28, 2024NewsroomHardware Security / Vulnerability

Cybersecurity researchers from ETH Zurich have developed a new variant of the RowHammer DRAM (dynamic random-access memory) attack that, for the first time, successfully works against AMD Zen 2 and Zen 3 systems despite mitigations such as Target Row Refresh (TRR).

“This result proves that AMD systems are equally vulnerable to Rowhammer as Intel systems, which greatly increases the attack surface, considering today’s AMD market share of around 36% on x86 desktop CPUs,” the researchers said.

The technique has been codenamed ZenHammer, which can also trigger RowHammer bit flips on DDR5 devices for the first time.

RowHammer, first publicly disclosed in 2014, is a well-known attack that exploits DRAM’s memory cell architecture to alter data by repeatedly accessing a specific row (aka hammering) to cause the electrical charge of a cell to leak to adjacent cells.

This can induce random bit flips in neighboring memory rows (from 0 to 1, or vice versa), which can alter the memory contents and potentially facilitate privilege escalation, compromising system credentials, integrity, and availability of a system.

The attacks take advantage of the physical proximity of these cells within the memory array, a problem that’s likely to worsen as the DRAM technology scaling continues and the storage density increases.

“As DRAM continues to scale, RowHammer bit flips can occur at smaller activation counts and thus a benign workload’s DRAM row activation rates can approach or even exceed the RowHammer threshold,” ETH Zurich researchers noted in a paper published in November 2022.

“Thus, a system may experience bit flips or frequently trigger RowHammer defense mechanisms even without a malicious party performing a RowHammer attack in the system, leading to data corruption or significant performance degradation.”

One of the crucial mitigations implemented by DRAM manufacturers against RowHammer is TRR, which is an umbrella term used for mechanisms that refresh target rows that are determined to be accessed frequently.

In doing so, the idea is to generate more memory refresh operations so that victim rows will either be refreshed before bits are flipped or be corrected after bits are flipped due to RowHammer attacks.

ZenHammer, like TRRespass and SMASH, bypasses TRR guardrails by reverse engineering the secret DRAM address functions in AMD systems and adopting improved refresh synchronization and scheduling of flushing and fencing instructions to trigger bit flips on seven out of 10 sample Zen 2 devices and six out of 10 Zen 3 devices.

The study also arrived at an optimal hammering instruction sequence to improve row activation rates in order to facilitate more effective hammering.

“Our results showed that regular loads (MOV) with CLFLUSHOPT for flushing aggressors from the cache, issued immediately after accessing an aggressor (‘scatter’ style), is optimal,” the researchers said.

ZenHammer has the distinction of being the very first method that can trigger bit flips on systems equipped with DDR5 chips on AMD’s Zen 4 microarchitectural platform. That said, it only works on one of the 10 tested devices (Ryzen 7 7700X).

It’s worth noting that DDR5 DRAM modules were previously considered immune to RowHammer attacks owing to them replacing TRR with a new kind of protection called refresh management.

“The changes in DDR5 such as improved RowHammer mitigations, on-die error correction code (ECC), and a higher refresh rate (32 ms) make it harder to trigger bit flip,” the researchers said.

“Given the lack of bit flips on nine of 10 DDR5 devices, more work is needed to better understand the potentially new RowHammer mitigations and their security guarantees.”

AMD, in a security bulletin, said it’s assessing RowHammer bit flips on DDR5 devices, and that it will provide an update following its completion.

“AMD microprocessor products include memory controllers designed to meet industry-standard DDR specifications,” it added. “Susceptibility to RowHammer attacks varies based on the DRAM device, vendor, technology, and system settings.”

Mar 27, 2024NewsroomVulnerability / Cybercrime

A new phishing campaign has been observed leveraging a novel loader malware to deliver an information stealer and keylogger called Agent Tesla.

Trustwave SpiderLabs said it identified a phishing email bearing this attack chain on March 8, 2024. The message masquerades as a bank payment notification, urging the user to open an archive file attachment.

The archive (“Bank Handlowy w Warszawie – dowód wpłaty_pdf.tar.gz”) conceals a malicious loader that activates the procedure to deploy Agent Tesla on the compromised host.

“This loader then used obfuscation to evade detection and leveraged polymorphic behavior with complex decryption methods,” security researcher Bernard Bautista said in a Tuesday analysis.

“The loader also exhibited the capability to bypass antivirus defenses and retrieved its payload using specific URLs and user agents leveraging proxies to further obfuscate traffic.”

The tactic of embedding malware within seemingly benign files is a tactic that has been repeatedly employed by threat actors to trick unsuspecting victims into triggering the infection sequence.

The loader used in the attack is written in .NET, with Trustwave discovering two distinct variants that each make use of a different decryption routine to access its configuration and ultimately retrieve the XOR-encoded Agent Tesla payload from a remote server.

In an effort to evade detection, the loader is also designed to bypass the Windows Antimalware Scan Interface (AMSI), which offers the ability for security software to scan files, memory, and other data for threats.

It achieves this by “patching the AmsiScanBuffer function to evade malware scanning of in-memory content,” Bautista explained.

The last phase involves decoding and executing Agent Tesla in memory, allowing the threat actors to stealthily exfiltrate sensitive data via SMTP using a compromised email account associated with a legitimate security system supplier in Turkey (“merve@temikan[.]com[.]tr”).

The approach, Trustwave said, not only does not raise any red flags, but also affords a layer of anonymity that makes it harder to trace the attack back to the adversary, not to mention save the effort of having to set up dedicated exfiltration channels.

“[The loader] employs methods like patching to bypass Antimalware Scan Interface (AMSI) detection and dynamically load payloads, ensuring stealthy execution and minimizing traces on disk,” Bautista said. “This loader marks a notable evolution in the deployment tactics of Agent Tesla.”

The disclosure comes as BlueVoyant uncovered another phishing activity conducted by a cybercrime group called TA544 that leverages PDFs dressed up as legal invoices to propagate WikiLoader (aka WailingCrab) and establish connections with command-and-control (C2) server that almost exclusively encompasses hacked WordPress sites.

It’s worth noting that TA544 also weaponized a Windows security bypass flaw tracked as CVE-2023-36025 in November 2023 to distribute Remcos RAT via a different loader family dubbed IDAT Loader, allowing it to seize control of infected systems.

The findings also follow a surge in the use of a phishing kit called Tycoon, which Sekoia said has “become one of the most widespread [adversary-in-the-middle] phishing kits over the last few months, with more than 1,100 domain names detected between late October 2023 and late February 2024.”

Tycoon, publicly documented by Trustwave last month, permits cyber criminals to target users of Microsoft 365 with phony login pages to capture their credentials, session cookies, and two-factor authentication (2FA) codes. It’s known to be active since at least August 2023, with the service offered via private Telegram channels.

The phishing kit is notable for incorporating extensive traffic filtering methods to thwart bot activity and analysis attempts, requiring site visitors to complete a Cloudflare Turnstile challenge before redirecting users to a credential harvesting page.

Tycoon also shares operational and design-level similarities with the Dadsec OTT phishing kit, raising the possibility that the developers had access to and tweaked the source code of the latter to suit their needs. This is supported by the fact that Dadsec OTT had its source code leaked in October 2023.

“The developer enhanced stealth capabilities in the most recent version of the phishing kit,” Sekoia said. “The recent updates could reduce the detection rate by security products of the Tycoon 2FA phishing pages and the infrastructure. Additionally, its ease of use and its relatively low price make it quite popular among threat actors.”

Mar 25, 2024NewsroomSupply Chain Attack / Cryptocurrency

Unidentified adversaries orchestrated a sophisticated attack campaign that has impacted several individual developers as well as the GitHub organization account associated with Top.gg, a Discord bot discovery site.

“The threat actors used multiple TTPs in this attack, including account takeover via stolen browser cookies, contributing malicious code with verified commits, setting up a custom Python mirror, and publishing malicious packages to the PyPI registry,” Checkmarx said in a technical report shared with The Hacker News.

The software supply chain attack is said to have led to the theft of sensitive information, including passwords, credentials, and other valuable data. Some aspects of the campaign were previously disclosed at the start of the month by an Egypt-based developer named Mohammed Dief.

It chiefly entailed setting up a clever typosquat of the official PyPI domain known as “files.pythonhosted[.]org,” giving it the name “files.pypihosted[.]org” and using it to host trojanized versions of well-known packages like colorama. Cloudflare has since taken down the domain.

“The threat actors took Colorama (a highly popular tool with 150+ million monthly downloads), copied it, and inserted malicious code,” Checkmarx researchers said. “They then concealed the harmful payload within Colorama using space padding and hosted this modified version on their typosquatted-domain fake-mirror.”

These rogue packages were then propagated via GitHub repositories such as github[.]com/maleduque/Valorant-Checker and github[.]com/Fronse/League-of-Legends-Checker that contained a requirements.txt file, which serves as the list of Python packages to be installed by the pip package manager.

One repository that continues to remain active as of writing is github[.]com/whiteblackgang12/Discord-Token-Generator, which includes a reference to the malicious version of colorama hosted on “files.pypihosted[.]org.”

Also altered as part of the campaign is the requirements.txt file associated with Top.gg’s python-sdk by an account named editor-syntax on February 20, 2024. The issue has been addressed by the repository maintainers.

It’s worth noting that the “editor-syntax” account is a legitimate maintainer of the Top.gg GitHub organization and has written permissions to Top.gg’s repositories, indicating that the threat actor managed to hijack the verified account in order to commit a malicious commit.

“The GitHub account of ‘editor-syntax’ was likely hijacked through stolen cookies,” Checkmarx noted.

“The attacker gained access to the account’s session cookies, allowing them to bypass authentication and perform malicious activities using the GitHub UI. This method of account takeover is particularly concerning, as it does not require the attacker to know the account’s password.”

What’s more, the threat actors behind the campaign are said to have pushed multiple changes to the rogue repositories in one single commit, altering as many as 52 files in one instance in an effort to conceal the changes to the requirements.txt file.

The malware embedded in the counterfeit colorama package activates a multi-stage infection sequence that leads to the execution of Python code from a remote server, which, in turn, is capable of establishing persistence on the host via Windows Registry changes and stealing data from web browsers, crypto wallets, Discord tokens, and sessions tokens related to Instagram and Telegram.

“The malware includes a file stealer component that searches for files with specific keywords in their names or extensions,” the researchers said. “It targets directories such as Desktop, Downloads, Documents, and Recent Files.”

The captured data is ultimately transferred to the attackers via anonymous file-sharing services like GoFile and Anonfiles. Alternately, the data is also sent to the threat actor’s infrastructure using HTTP requests, alongside the hardware identifier or IP address to track the victim machine.

“This campaign is a prime example of the sophisticated tactics employed by malicious actors to distribute malware through trusted platforms like PyPI and GitHub,” the researcher concluded.

“This incident highlights the importance of vigilance when installing packages and repositories even from trusted sources. It is crucial to thoroughly vet dependencies, monitor for suspicious network activity, and maintain robust security practices to mitigate the risk of falling victim to such attacks.”

Mar 20, 2024NewsroomDoS Attack / Network Security

A novel denial-of-service (DoS) attack vector has been found to target application-layer protocols based on User Datagram Protocol (UDP), putting hundreds of thousands of hosts likely at risk.

Called Loop DoS attacks, the approach pairs “servers of these protocols in such a way that they communicate with each other indefinitely,” researchers from the CISPA Helmholtz-Center for Information Security said.

UDP, by design, is a connectionless protocol that does not validate source IP addresses, making it susceptible to IP spoofing.

Thus, when attackers forge several UDP packets to include a victim IP address, the destination server responds to the victim (as opposed to the threat actor), creating a reflected denial-of-service (DoS) attack.

The latest study found that certain implementations of the UDP protocol, such as DNS, NTP, TFTP, Active Users, Daytime, Echo, Chargen, QOTD, and Time, can be weaponized to create a self-perpetuating attack loop.

“It pairs two network services in such a way that they keep responding to one another’s messages indefinitely,” the researchers said. “In doing so, they create large volumes of traffic that result in a denial-of-service for involved systems or networks. Once a trigger is injected and the loop set in motion, even the attackers are unable to stop the attack.”

Put simply, given two application servers running a vulnerable version of the protocol, a threat actor can initiate communication with the first server by spoofing the address of the second server, causing the first server to respond to the victim (i.e., the second server) with an error message.

The victim, in turn, will also exhibit similar behavior, sending back another error message to the first server, effectively exhausting each other’s resources and making either of the services unresponsive.

“If an error as input creates an error as output, and a second system behaves the same, these two systems will keep sending error messages back and forth indefinitely,” Yepeng Pan and Christian Rossow explained.

CISPA said an estimated 300,000 hosts and their networks can be abused to carry out Loop DoS attacks.

While there is currently no evidence that the attack has been weaponized in the wild, the researchers warned that exploitation is trivial and that multiple products from Broadcom, Cisco, Honeywell, Microsoft, MikroTik, and Zyxel are affected.

“Attackers need a single spoofing-capable host to trigger loops,” the researchers noted. “As such, it is important to keep up initiatives to filter spoofed traffic, such as BCP38.”