A steganographic coding detector (and method) analyzes one or more pages of a file. For each page containing text strings, the detector counts a number of A0h and 20h characters for the text string. For each text string for which the number of A0h characters is greater than a first threshold, the detector sets a flag to a first state, The first threshold is computed based on the number of 20h characters in that text string. For each text string for which the number of 20h characters is less than the first threshold, the detector sets the flag to a second state. Responsive to the number of text strings that have a flag at the first state being greater than a second threshold, the detector marks the file as being steganographically encoded.