Core Viewpoint - British retailer Marks & Spencer experienced a significant decline in first-half underlying profit, dropping by 55.4%, primarily due to the adverse effects on sales and margins from a cyber hack incident in April that led to the suspension of online clothing orders [1] Financial Performance - The first-half underlying profit fell by 55.4%, indicating a substantial impact on the company's financial health [1] - The cyber hack incident in April directly affected sales and margins, highlighting vulnerabilities in the company's online operations [1] Operational Impact - The cyber hack forced Marks & Spencer to suspend online clothing orders, which contributed to the decline in sales [1] - The incident underscores the importance of cybersecurity measures in protecting retail operations and maintaining customer trust [1]