Here is a list of extensions that could be excluded from being scanned. Feel free to add your own.
aac, acs, adc, adm, ai, am, art, avi, awe, bat, bin, bkf, bmp, cab, cat, cfg, chm, class, clx, cmd, cnt, cnv, com, config, cpl, cpp, cs, csf, css, cur, cw, dic, dll, dlm, dotx, env, eps, evt, evtx, exe, flt, fon, gif, h, hhk, hiv, hlp, hxs, hxw, hyp, icc, icm, ico, idx, inf, ini, iso, its, jar, jpeg, jpg, js, jse, lex, lib, liveupdate, lnk, lxa, m4a, m4p, m4v, mda, mdf, mid, mof, mov, mp3, mp4, mpeg, mpg, msc, msi, msp, mst, ngr, ocx, ogg, olb, pf, pfb, pfm, pnf, png, ps1, psd, psp, py, pyw, query, rll, rm, rmm, rmx, rp, rpm, rpv, rts, sdb, smi, spd, swp, sys, theme, tif, tiff, toc, ttc, ttf, vb, vbe, vbn, vbs, vhd, vmdk, vsd, wav, wma, wmb, wmdb, wmv, wpc, wsf, wsh, xaml, xdr, xml