Short answer: the exact dress is a Polo Ralph Lauren striped silk‑blend midi (the one Taylor Swift wore), and you can try Ralph Lauren stores in Kuala Lumpur or buy similar/dupe styles from Malaysian retailers and online sellers.

Where to look (quick list)

• Ralph Lauren boutiques in KL (Suria KLCC and Pavilion) — best first stop to try to get the same Polo Ralph Lauren dress in Malaysia. (fashionista.com)
• Ralph Lauren’s online store (check the Malaysia site or call the local boutiques if the item is sold out online). (glamour.com)
• Malaysian fast‑to‑mid market & local brands that carry similar ruched/smocked striped midis: Love, Bonito and Mango Malaysia (good for affordable dupes). (lovebonito.com)
• Big local marketplace and multi‑brand e‑retailer: Zalora Malaysia — search “ruched midi”, “smocked midi” or “striped midi.” (zalora.com.my)
• If you want higher‑end designer alternatives or more curated dupes, international multi‑retailers that ship to Malaysia (The Outnet / Net‑A‑Porter / Farfetch) have ruched/striped midi options. (theoutnet.com)

Notes and tips

• The dress Swift wore was widely reported as a Polo Ralph Lauren striped silk‑blend midi (priced around the low‑to‑mid US$300s at release), so start with Ralph Lauren stock or customer service. (fashionista.com)
• If the exact style is sold out, use search terms like: “ruched smocked bodice striped midi dress,” “smocked striped midi,” or “ruched halter midi” on the sites above to find very similar shapes and fabrics. (shop.mango.com)
• For a Taylor‑like casual finish, pair a striped silk/blend midi with flat brown sandals (Swift styled hers that way) and a simple watch/bracelet. (parade.com)

If you want, I can:

• Check current stock for that exact Polo Ralph Lauren dress at the Suria KLCC or Pavilion boutiques and/or Ralph Lauren’s Malaysia site right now; or
• Search Zalora, Love, Bonito and The Outnet for specific in‑stock dresses that match the look and send links/prices.

Which would you prefer?