Adobe acrobat PDF generated in the United states displaying incorrect characters for foreign customers.

I see two possibilities. (A) You're using a non-standard font, or (B) your customer has got something wrong with their computer.

Numbers are pretty standard across all fonts, so even if you're trying to view the document using the wrong font, the numbers should remain numbers, not swap for characters (symbol fonts like Windings excepted). So I'd tend to favor explanation (B). Do any of your other UAE customers report the same problem? Or if this is your only UAE customer, have they tried viewing the PDF on another computer?

For explanation (A), track down the person(s) creating the document you're converting to a PDF. They've probably got some weird font installed and are using it because they think it looks slightly better. On other people's computers, Acrobat (or whatever PDF reader is being used) doesn't recognize the font so tries to swap it for the next closest thing. The U.S. version is probably swapping it for a different font than the UAE version.

This is one of the reasons you should always use standard fonts when creating documents for widespread distribution. Non-standard fonts need to be licensed by the programs or OS using them, else they won't be available. Microsoft, Adobe, etc. have gone through the trouble to create, buy, or pay for global licenses for standard fonts included with Windows or Adobe software so their customers can use them without having to deal with these sorts of issues. If your employee complains that their weird font looks so much better, point out that since they're the only ones who have it installed, they're the only ones seeing it. Everyone else is seeing the software's best guess at the closest equivalent font.

(Occasionally this issue crops up with PC documents viewed on a Mac, or vice versa. Though I believe Apple used Adobe fonts, and Microsoft's equivalent fonts were deliberately designed with the same character size and kerning to avoid this problem.)