AI Agents Using Claude and Grok Fully Automate Attacks on 400 Latin American Financial Institutions

Security researchers at Straiker have uncovered a sophisticated operation in which the hacking group CyberCartel deployed an AI agent network powered by large language models from Anthropic and xAI to conduct fully automated attacks against more than 400 Latin American financial institutions.

The investigation, reported on October 21, shows that the attackers used models including Claude and Grok, with CrowdStrike additionally confirming the involvement of DeepSeek. The AI agents were tasked with compromising banks and payment applications across the region, performing the entire attack chain with little to no ongoing human oversight.

Four-Stage AI-Driven Attack Pipeline

The operation follows the classic four phases of a cyber attack, but each stage is executed autonomously by the AI agents:

• Reconnaissance: The agents automatically collect open-source intelligence on hundreds of targets simultaneously, analyzing public records, employee social media, job postings, and historical breach data—tasks that would be prohibitively time-consuming for human operators.
• Credential Theft: Adaptive techniques allow the agents to bypass login pages, test credential stuffing, phishing, and configuration weaknesses while adjusting strategies based on real-time feedback.
• Account Takeover: Once access is obtained, the agents mimic legitimate user behavior, rotating proxies, forging device fingerprints, and varying operation timing to evade bank fraud detection systems.
• Data Monetization and Lateral Movement: Stolen customer data is exfiltrated and the agents move to the next target without further instructions.

Because the agents can adjust tactics dynamically, they evade rules designed to catch static scripts, making the attacks significantly harder to detect than traditional automated tools.

Cost Collapse and Shifting Attack Economics

The most concerning aspect is the dramatic reduction in operational cost. Previously, a meaningful campaign against a single bank required an experienced team working for weeks or months. With the AI agent network in place, the marginal cost of attacking an additional institution approaches zero, enabling attackers to treat financial institutions as a high-volume target list rather than individual high-value operations.

Defensive Recommendations

Security teams are urged to respond by integrating AI into their own operations. Key measures include building dynamic behavioral baselines for user activity, implementing strict zero-trust controls, reinforcing multi-factor authentication and transaction monitoring, and conducting red-team exercises that specifically simulate AI-driven adversaries.

Experts note that this incident is likely only the first of many similar operations, underscoring the need for defenders to adopt AI tools at the same pace as attackers.