WinRAR path-traversal (referenced as initial-access exploit in Gamaredon GammaPhish/GammaWorm campaign, Sekoia 2026-06-01)

Adversaries may send phishing messages to gain access to victim systems. All forms of phishing are electronically delivered social engineering. Phishing can be targeted, known as spearphishing. In spearphishing, a specific individual, company, or industry will be targeted by the adversary. More generally, adversaries can conduct non-targeted phishing, such as in mass malware spam campaigns.

Evidence: 2026-06-27/turla-s-stockstay-a-four-component-net-backdoor-for-diplomat · ATT&CK page ↗

Adversaries may send spearphishing emails with a malicious attachment in an attempt to gain access to victim systems. Spearphishing attachment is a specific variant of spearphishing. Spearphishing attachment is different from other forms of spearphishing in that it employs the use of malware attached to an email. All forms of spearphishing are electronically delivered social engineering targeted at a specific individual, company, or industry. In this scenario, adversaries attach a file to the spearphishing email and usually rely upon User Execution to gain execution. Spearphishing may also involve social engineering techniques, such as posing as a trusted source.

Evidence: 2026-06-27/turla-s-stockstay-a-four-component-net-backdoor-for-diplomat · ATT&CK page ↗

Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries. These interfaces and languages provide ways of interacting with computer systems and are a common feature across many different platforms. Most systems come with some built-in command-line interface and scripting capabilities, for example, macOS and Linux distributions include some flavor of Unix Shell while Windows installations include the Windows Command Shell and PowerShell.

Evidence: 2026-06-27/turla-s-stockstay-a-four-component-net-backdoor-for-diplomat · ATT&CK page ↗

Adversaries may abuse Visual Basic (VB) for execution. VB is a programming language created by Microsoft with interoperability with many Windows technologies such as Component Object Model and the Native API through the Windows API. Although tagged as legacy with no planned future evolutions, VB is integrated and supported in the .NET Framework and cross-platform .NET Core.

Evidence: 2026-06-10/year-old-winrar-flaw-cve-2025-8088-still-fuels-ukraine-intru · ATT&CK page ↗

Adversaries may configure system settings to automatically execute a program during system boot or logon to maintain persistence or gain higher-level privileges on compromised systems. Operating systems may have mechanisms for automatically running a program on system boot or account logon. These mechanisms may include automatically executing programs that are placed in specially designated directories or are referenced by repositories that store configuration information, such as the Windows Registry. An adversary may achieve the same goal by modifying or extending features of the kernel.

Evidence: 2026-06-27/turla-s-stockstay-a-four-component-net-backdoor-for-diplomat · ATT&CK page ↗

Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the "run keys" in the Registry or startup folder will cause the program referenced to be executed when a user logs in. These programs will be executed under the context of the user and will have the account's associated permissions level.

Evidence: 2026-06-27/turla-s-stockstay-a-four-component-net-backdoor-for-diplomat · 2026-06-10/year-old-winrar-flaw-cve-2025-8088-still-fuels-ukraine-intru · ATT&CK page ↗

Adversaries may configure system settings to automatically execute a program during system boot or logon to maintain persistence or gain higher-level privileges on compromised systems. Operating systems may have mechanisms for automatically running a program on system boot or account logon. These mechanisms may include automatically executing programs that are placed in specially designated directories or are referenced by repositories that store configuration information, such as the Windows Registry. An adversary may achieve the same goal by modifying or extending features of the kernel.

Evidence: 2026-06-27/turla-s-stockstay-a-four-component-net-backdoor-for-diplomat · ATT&CK page ↗

Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the "run keys" in the Registry or startup folder will cause the program referenced to be executed when a user logs in. These programs will be executed under the context of the user and will have the account's associated permissions level.

Evidence: 2026-06-27/turla-s-stockstay-a-four-component-net-backdoor-for-diplomat · 2026-06-10/year-old-winrar-flaw-cve-2025-8088-still-fuels-ukraine-intru · ATT&CK page ↗

Adversaries may use execution guardrails to constrain execution or actions based on adversary supplied and environment specific conditions that are expected to be present on the target. Guardrails ensure that a payload only executes against an intended target and reduces collateral damage from an adversary’s campaign. Values an adversary can provide about a target system or environment to use as guardrails may include specific network share names, attached physical devices, files, joined Active Directory (AD) domains, and local/external IP addresses.

Evidence: 2026-06-27/turla-s-stockstay-a-four-component-net-backdoor-for-diplomat · ATT&CK page ↗

Adversaries may acquire credentials from web browsers by reading files specific to the target browser. Web browsers commonly save credentials such as website usernames and passwords so that they do not need to be entered manually in the future. Web browsers typically store the credentials in an encrypted format within a credential store; however, methods exist to extract plaintext credentials from web browsers.

Evidence: 2026-06-10/year-old-winrar-flaw-cve-2025-8088-still-fuels-ukraine-intru · ATT&CK page ↗

Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.

Evidence: 2026-06-27/turla-s-stockstay-a-four-component-net-backdoor-for-diplomat · ATT&CK page ↗

Adversaries may communicate using OSI application layer protocols to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.

Evidence: 2026-06-27/turla-s-stockstay-a-four-component-net-backdoor-for-diplomat · ATT&CK page ↗

Adversaries may communicate using application layer protocols associated with web traffic to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.

Evidence: 2026-06-27/turla-s-stockstay-a-four-component-net-backdoor-for-diplomat · ATT&CK page ↗

Adversaries may steal data by exfiltrating it over an existing command and control channel. Stolen data is encoded into the normal communications channel using the same protocol as command and control communications.

Evidence: 2026-06-27/turla-s-stockstay-a-four-component-net-backdoor-for-diplomat · ATT&CK page ↗