Threat briefs

This brief details the detection of unencrypted Telnet traffic on its default port 23, a legacy protocol commonly used for remote administration but frequently exploited by threat actors for initial access or as a backdoor due to its plain-text nature, which exposes sensitive information and facilitates unauthorized access.

Threat actors frequently exploit internet-exposed Remote Procedure Call (RPC) services, primarily on port TCP/135, as an initial access or backdoor vector, leading to unauthorized system access, internal network compromise, and potentially data exfiltration or ransomware deployment.

The BadPatch malware family utilizes SMTP on TCP port 26 for covert command and control of Windows systems, an atypical port for SMTP, posing a significant risk of unauthorized access and data exfiltration.

Detects the first direct invocation of an AWS Lambda function by a principal within a 14-day period, excluding AWS service invocations, which can indicate adversary lateral movement, credential abuse, or unauthorized data retrieval in AWS environments.

Attackers are abusing stolen AWS execution-role or user credentials to invoke AWS Lambda functions from unusual source networks (ASNs) not previously associated with the legitimate principal, indicating a credential compromise leading to potential unauthorized access or data exfiltration.

Adversaries leverage the `DeleteImportedKeyMaterial` API call against AWS KMS customer managed keys (CMKs) with external material, instantly rendering encrypted data inaccessible with no recovery window, facilitating cloud ransomware or data destruction attacks.

Adversaries leverage cross-account access to invoke AWS Lambda functions from a different account than the function owner, enabling code execution or data retrieval, which requires AWS Lambda data event logging to detect.

Adversaries are leveraging the AWS Backup `DeleteRecoveryPoint` API call by non-service principals to remove critical data backups, a high-signal anti-recovery technique observed in ransomware and data-destruction attacks that prevents victims from restoring associated data.

An adversary can achieve privilege escalation within an AWS environment by modifying or removing an existing IAM permissions boundary on an IAM user or role, thereby unlocking previously restricted permissions defined in attached identity policies.

Adversaries can escalate privileges and establish persistence within AWS by leveraging the `PutGroupPolicy` API call to attach an inline policy to an IAM group, granting broad permissions to all group members, including themselves.

A detection rule identifies suspicious outbound IPSEC NAT Traversal (NAT-T) tunnels, characterized by UDP traffic where both source and destination ports are 4500, originating from an internal host to an external destination, a technique frequently abused by threat actors to establish covert command and control channels or exfiltrate data while evading network defenses.

This rule detects the creation or modification of console login profiles for AWS IAM users via the CreateLoginProfile or UpdateLoginProfile APIs. Adversaries with stolen programmatic credentials can use these actions to establish persistent interactive console access, reset other users' passwords to take over accounts, and maintain access even after original access keys are rotated. Since IAM user console access is increasingly managed through federation or IAM Identity Center, direct use of these APIs, especially by unexpected principals, warrants investigation as a strong indicator of persistence or account compromise.

An adversary is detected performing anti-recovery actions in AWS Backup by deleting backup vaults or removing their Vault Lock configurations via the DeleteBackupVault or DeleteBackupVaultLockConfiguration API calls, serving as a strong precursor to ransomware or data destruction, preventing organizations from restoring critical data.

An Elastic Defend for Containers rule detects interactive sessions within Linux containers where `curl` or `wget` are used to download files from the internet, indicating potential adversary command and control or execution activity as threat actors often use such methods to stage payloads, tools, or data for subsequent malicious actions within compromised containerized environments.

This brief describes a behavioral detection for Windows hosts where two or more distinct remote monitoring and management (RMM) or remote-access tools from different vendors are observed starting processes within an eight-minute window, indicating potential compromise, shadow IT, or attacker staging of redundant access.

Detection rule identifies inbound Windows file sharing (SMB/CIFS) traffic originating from the Internet to internal hosts, posing a critical initial access risk due to potential exploitation of vulnerabilities like CVE-2017-0144 (EternalBlue).

Adversaries leverage adversary-in-the-middle (AiTM) phishing and session theft to compromise AWS IAM user credentials, leading to concurrent successful AWS Management Console logins from multiple distinct geographic locations, indicating account compromise and enabling unauthorized access to cloud resources despite MFA.

This brief details how attackers can leverage compromised AWS credentials to inject malicious, base64-encoded scripts into Amazon SageMaker notebook lifecycle configurations, which then execute as root on notebook instances, enabling persistence, credential theft, or further compromise of the AWS environment.

A malicious actor or misconfigured legitimate user can modify an Amazon ECR repository or registry policy to grant public access using a wildcard principal (`Principal:"*"`), which can lead to the exfiltration of proprietary container images and embedded secrets, or facilitate supply-chain implantation if push permissions are also granted.

This brief details the detection of potential SQL injection (SQLi) attempts against web servers by identifying common SQLi patterns in URLs and query strings, used by threat actors for reconnaissance, data exfiltration, or command execution, aiming for sensitive information disclosure or system compromise.

Adversaries are leveraging legitimate Remote Monitoring and Management (RMM) and remote access tools on Windows endpoints for command-and-control, persistence, and execution, with detection focusing on the first observed instance of these tools on a host.

Threat actors with root privileges can leverage built-in Linux utilities like `insmod` or `modprobe` to load kernel object files, often for installing rootkits that grant complete system control and enable evasion of security products, representing a significant persistence and defense evasion technique.

Adversaries employ Base64 encoding to obfuscate malicious payloads, which are then decoded and executed by interpreters like `bash`, `python`, `perl`, or `ruby` on Linux systems, aiming to evade host- or network-based security controls by piping the output of decoding tools directly to command-line interpreters for arbitrary code execution.

Attackers are actively exploiting Server-Side Request Forgery (SSRF) vulnerabilities in public-facing web applications to access cloud instance metadata services, such as those on AWS, GCP, and Azure, to harvest temporary credentials and sensitive instance details.

This brief describes how to detect an attacker updating or replacing the Sysmon configuration with a bare bones one to avoid monitoring without completely shutting down the service, leveraging Sysmon's `-c` command-line option for defense impairment.

A Missing Authorization vulnerability, identified as CVE-2026-14460, in TUBITAK BILGEM Software Technologies Research Institute's pardus-software versions up to 1.0.4, allows for Argument Injection, posing a high severity risk to confidentiality, integrity, and availability.

This brief details a high-severity Linux privilege escalation technique where an attacker, having gained initial access, drops an exploit in a user- or world-writable directory, executes it as a non-root user, and the resulting child process changes its effective user ID to root (UID 0), thereby achieving full system compromise.

This brief describes a high-severity threat on Linux systems where attackers achieve local privilege escalation by executing a non-root process from a user- or world-writable directory that subsequently gains root privileges (UID 0), indicating a successful exploit to achieve full host compromise.

This brief details a high-severity threat where attackers exploit Linux systems to achieve local privilege escalation by executing a non-root process from a user- or world-writable directory (e.g., /tmp, /dev/shm) that subsequently changes its effective user ID to root (UID 0), indicating a successful abuse of a vulnerable setuid binary or kernel flaw to gain full system control.

Attackers can exploit a Linux kernel vulnerability allowing a process inside a container to modify the `/proc/sys/kernel/core_pattern` file, enabling the execution of arbitrary code as root on the host system upon a core-dump, thereby achieving a full container-to-host escape and privilege escalation.