In just six years, Marks & Spencer has transformed into a fashion destination with increased profits and sales.A recent cyber-attack disrupting online clothing sales poses a threat to M&S's fashion strategy.The disruption is expected to lead to £300m in lost profits, impacting brand reputation and customer loyalty.Strong clothing sales are attributed to wardrobe basics like underwear and more fashion-forward pieces.M&S's focus on a more fashion-focused demographic has been pivotal in its turnaround.The retailer introduced designer collaborations and standalone brands to appeal to customers.M&S has reduced design time to market and gained success with high-quality dupes of high-end products.Customers have expressed frustrations on social media due to the cyber-attack impact on shopping.Retail analysts believe loyal M&S customers may explore other brands due to the online disruption.The impact of the cyber-attack on M&S's strategy is seen as a temporary setback rather than a permanent derailment.