In Germany, the problem of militaria forgeries is greatly less than in North America because as soon as a forgery is noted on the market, it's quickly documented and published.  In about August 2006, an excellent forgery of the 3rd Reich Infantry Assault Badge (in bronze) was noted as being introduced into the market.  While excellent, there are some distinguishing characteristics that make it readily identifiable.  Unfortunately, I can not illustrate it on eBay due to copyright of the photos.

An Infantriesturmabzeichen (Infantry Assault Badge) in bronze appears to have been recently stamped from the Hymmen & Co. (Lüdenscheid) hollow back original dies - this point is important to note since most examples are solid backs and a hollow back typically attracts a premium price!  Hymmen & Co. usually marked their badges just L/53 (rarely H & Co. L and even rarer unmarked).  This particular example is unmarked but appears to be from the same obverse die as known Hymmen & Co. examples.  The metal used is tombak and is generally of an extraordinarily high quality which will easily deceive most collectors. 

The obverse has only 1 distinguishing feature:  the Hakenkreuz (swastika) has the 3 lower arms very finely finished so there is no metal connecting each arm in the background.  It's what is called a skeleton cross.  The forgery also has the left wing (as viewed) cut out and away from the cross - the original unmarked Hymmen & Co. example has a filler background.  The right wing is the same in both cases. 

The reverse has many distinguishing features:  the stickpin has been artificially colored where it has been cut during the manufacturing process, the stickpin locking loop is of a C form (rather than a ? form and is located almost 2mm higher than the original, the stickpin fixed mount is about 1 to 2 mm wider than the original and is in the form of a keyhole type rather than a log & base type,  and - so far - the forgeries do not show signs of artifical aging.  All of these distinguishing features have been done extremely well, making it an absolutely 1st class example.  The Germans have labeled this an overly-attractive forgery.

Note that this information is for the Hymmen & Co. version only.  By September 2006, no examples of this badge in silver or gold were noted as being on the market - only the bronze version.  Until detected and reported, this particular badge was bringing a premium price (ca. €150!!)  due to the extraordinarily high quality.  Once it was detected, the market for this particular badge stopped until an evaluation could be conducted and published.  I suspect that these forged examples will be moved to other markets which don't have access to this data.  A common example typically sells in the $50+ range but original specimans similar in quality to this sell for at least double that amount.  This particular badge can not be listed on eBay but many eBayers collect these from other sources.  Germany's militaria forgery alert system is excellent!   For further information on medals, please see my other guides and blog (http://blogs.ebay.com/tsa-li) - particularly the guides relating to collecting WWII German items.  Please note that I do not collect, buy, sell, or trade 3rd Reich items but I do have access to a tremendous amount of information concerning them.  Thanks for viewing!