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338 Million Attack Simulations Reveal The State Of Enterprise Defense

Picus Labs' Blue Report 2026, from 338 million attack simulations, finds defenses strong at the perimeter but blocking only 37% of post-compromise actions.

Picus Labs' fourth annual Blue Report analyzed over 338 million attack simulations from production environments in H1 2026. Average prevention effectiveness rose from 62% to 69%, but only 37% of attacker actions were blocked after compromise, with reconnaissance and credential theft largely missed. IOC-based malware download prevention fell to 50% from 71% in 2024, and Mimikatz credential dumping from LSASS memory was blocked 94% of the time versus 17% from other memory locations and 3% from registry.

Help Net Security · Aug 12, 2026Research

Your Shredded Visa Card May Still Work at the Checkout

UMass Amherst researchers demonstrated expired Visa contactless cards can complete real purchases via relay attacks exploiting Visa Kernel 3's unsigned expiry date handling.

University of Massachusetts Amherst researchers presented at USENIX Security 2026 that expired Visa contactless cards can be revived for real purchases through an NFC man-in-the-middle attack on Visa's Kernel 3. The attack alters the expiry date the terminal sees (tag 5F24) while leaving the Track 2 Equivalent Data (tag 57) sent to the issuing bank unchanged, and the card's cryptographic signature does not cover the expiry date. Two Android phones emulating card and terminal relayed transactions within Visa's 500-millisecond limit. Mastercard, American Express, and Discover kernels blocked the attack, while Visa Kernel 3 did not; researchers also modified the Consumer Device Cardholder Verification Method flag at five US banks, and attackers can also exploit Terminal Verification Results zero-filling. Visa was notified in May 2025 and December 2025; no CVE has been assigned.

Security Affairs · 26d agoResearch