identifyすると明らかにColormapが怪しい。
$ identify nyan-task.png
Image: nyan-task.png
Format: PNG (Portable Network Graphics)
Mime type: image/png
Class: PseudoClass
Geometry: 2880x1800+0+0
Units: Undefined
Type: Palette
Endianess: Undefined
Colorspace: sRGB
Depth: 8-bit
Channel depth:
red: 8-bit
green: 8-bit
blue: 8-bit
Channel statistics:
Pixels: 5184000
Red:
min: 0 (0)
max: 255 (1)
mean: 43.8393 (0.171919)
standard deviation: 79.7453 (0.312727)
kurtosis: 2.68596
skewness: 2.11637
entropy: 0.429713
Green:
min: 0 (0)
max: 255 (1)
mean: 82.6623 (0.324166)
standard deviation: 50.2157 (0.196924)
kurtosis: 3.40907
skewness: 2.01898
entropy: 0.395333
Blue:
min: 0 (0)
max: 255 (1)
mean: 119.863 (0.47005)
standard deviation: 53.7982 (0.210973)
kurtosis: 2.39776
skewness: 0.289517
entropy: 0.392986
Image statistics:
Overall:
min: 0 (0)
max: 255 (1)
mean: 82.1215 (0.322045)
standard deviation: 62.6503 (0.245687)
kurtosis: 2.27408
skewness: 1.31906
entropy: 0.406011
Colors: 14
Histogram:
136800: ( 0, 0, 0) #000000 black
102599: ( 2,161,255) #02A1FF srgb(2,161,255)
4065289: ( 11, 65,119) #0B4177 srgb(11,65,119)
92697: ( 48,233, 9) #30E909 srgb(48,233,9)
99900: (119, 85,255) #7755FF srgb(119,85,255)
103525: (167,167,167) #A7A7A7 srgb(167,167,167)
102600: (255, 43, 13) #FF2B0D srgb(255,43,13)
9000: (255, 91,179) #FF5BB3 srgb(255,91,179)
102600: (255,167, 2) #FFA702 srgb(255,167,2)
7200: (255,177,162) #FFB1A2 srgb(255,177,162)
157494: (255,178,255) #FFB2FF srgb(255,178,255)
54898: (255,210,158) #FFD29E srgb(255,210,158)
91798: (255,245, 0) #FFF500 srgb(255,245,0)
57600: (255,255,255) #FFFFFF white
Colormap entries: 256
Colormap:
0: ( 11, 65,119) #0B4177 srgb(11,65,119)
1: (255,177,162) #FFB1A2 srgb(255,177,162)
2: ( 11, 65,119) #0B4177 srgb(11,65,119)
3: (255,177,162) #FFB1A2 srgb(255,177,162)
4: ( 11, 65,119) #0B4177 srgb(11,65,119)
5: (255, 91,179) #FF5BB3 srgb(255,91,179)
6: ( 11, 65,119) #0B4177 srgb(11,65,119)
7: (255, 91,179) #FF5BB3 srgb(255,91,179)
8: ( 11, 65,119) #0B4177 srgb(11,65,119)
9: (255, 91,179) #FF5BB3 srgb(255,91,179)
10: ( 11, 65,119) #0B4177 srgb(11,65,119)
11: (255,210,158) #FFD29E srgb(255,210,158)
12: ( 11, 65,119) #0B4177 srgb(11,65,119)
13: (255,210,158) #FFD29E srgb(255,210,158)
14: ( 11, 65,119) #0B4177 srgb(11,65,119)
15: (255,255,255) #FFFFFF white
16: ( 11, 65,119) #0B4177 srgb(11,65,119)
17: (255,177,162) #FFB1A2 srgb(255,177,162)
18: (255,177,162) #FFB1A2 srgb(255,177,162)
19: ( 11, 65,119) #0B4177 srgb(11,65,119)
20: (255,210,158) #FFD29E srgb(255,210,158)
21: ( 11, 65,119) #0B4177 srgb(11,65,119)
22: ( 11, 65,119) #0B4177 srgb(11,65,119)
23: ( 11, 65,119) #0B4177 srgb(11,65,119)
24: (255,210,158) #FFD29E srgb(255,210,158)
25: ( 11, 65,119) #0B4177 srgb(11,65,119)
26: ( 11, 65,119) #0B4177 srgb(11,65,119)
27: (255,210,158) #FFD29E srgb(255,210,158)
28: ( 11, 65,119) #0B4177 srgb(11,65,119)
29: (255,210,158) #FFD29E srgb(255,210,158)
30: ( 11, 65,119) #0B4177 srgb(11,65,119)
31: ( 11, 65,119) #0B4177 srgb(11,65,119)
32: ( 11, 65,119) #0B4177 srgb(11,65,119)
33: ( 11, 65,119) #0B4177 srgb(11,65,119)
34: (255,177,162) #FFB1A2 srgb(255,177,162)
35: ( 11, 65,119) #0B4177 srgb(11,65,119)
36: (255,210,158) #FFD29E srgb(255,210,158)
37: (255,210,158) #FFD29E srgb(255,210,158)
38: (255,210,158) #FFD29E srgb(255,210,158)
39: (255,210,158) #FFD29E srgb(255,210,158)
40: (255,210,158) #FFD29E srgb(255,210,158)
41: (255,210,158) #FFD29E srgb(255,210,158)
42: (255,210,158) #FFD29E srgb(255,210,158)
43: (255,210,158) #FFD29E srgb(255,210,158)
44: (255,210,158) #FFD29E srgb(255,210,158)
45: (255,210,158) #FFD29E srgb(255,210,158)
46: ( 11, 65,119) #0B4177 srgb(11,65,119)
47: (255,245, 0) #FFF500 srgb(255,245,0)
48: ( 11, 65,119) #0B4177 srgb(11,65,119)
49: ( 11, 65,119) #0B4177 srgb(11,65,119)
50: ( 11, 65,119) #0B4177 srgb(11,65,119)
51: ( 11, 65,119) #0B4177 srgb(11,65,119)
52: ( 11, 65,119) #0B4177 srgb(11,65,119)
53: ( 11, 65,119) #0B4177 srgb(11,65,119)
54: (255,210,158) #FFD29E srgb(255,210,158)
55: ( 11, 65,119) #0B4177 srgb(11,65,119)
56: (255,210,158) #FFD29E srgb(255,210,158)
57: ( 11, 65,119) #0B4177 srgb(11,65,119)
58: ( 11, 65,119) #0B4177 srgb(11,65,119)
59: (255,210,158) #FFD29E srgb(255,210,158)
60: ( 11, 65,119) #0B4177 srgb(11,65,119)
61: ( 11, 65,119) #0B4177 srgb(11,65,119)
62: (255,245, 0) #FFF500 srgb(255,245,0)
63: ( 11, 65,119) #0B4177 srgb(11,65,119)
64: ( 11, 65,119) #0B4177 srgb(11,65,119)
65: (167,167,167) #A7A7A7 srgb(167,167,167)
66: (167,167,167) #A7A7A7 srgb(167,167,167)
67: ( 11, 65,119) #0B4177 srgb(11,65,119)
68: (255,210,158) #FFD29E srgb(255,210,158)
69: (255,210,158) #FFD29E srgb(255,210,158)
70: (255,210,158) #FFD29E srgb(255,210,158)
71: (255,210,158) #FFD29E srgb(255,210,158)
72: (255,210,158) #FFD29E srgb(255,210,158)
73: (255,210,158) #FFD29E srgb(255,210,158)
74: (255,210,158) #FFD29E srgb(255,210,158)
75: ( 11, 65,119) #0B4177 srgb(11,65,119)
76: ( 11, 65,119) #0B4177 srgb(11,65,119)
77: ( 11, 65,119) #0B4177 srgb(11,65,119)
78: (255,245, 0) #FFF500 srgb(255,245,0)
79: (255,245, 0) #FFF500 srgb(255,245,0)
80: ( 11, 65,119) #0B4177 srgb(11,65,119)
81: (167,167,167) #A7A7A7 srgb(167,167,167)
82: (167,167,167) #A7A7A7 srgb(167,167,167)
83: ( 11, 65,119) #0B4177 srgb(11,65,119)
84: (255,210,158) #FFD29E srgb(255,210,158)
85: (255,210,158) #FFD29E srgb(255,210,158)
86: ( 11, 65,119) #0B4177 srgb(11,65,119)
87: (255,210,158) #FFD29E srgb(255,210,158)
88: (255,210,158) #FFD29E srgb(255,210,158)
89: ( 11, 65,119) #0B4177 srgb(11,65,119)
90: ( 11, 65,119) #0B4177 srgb(11,65,119)
91: ( 11, 65,119) #0B4177 srgb(11,65,119)
92: (255,167, 2) #FFA702 srgb(255,167,2)
93: (255,167, 2) #FFA702 srgb(255,167,2)
94: ( 11, 65,119) #0B4177 srgb(11,65,119)
95: ( 11, 65,119) #0B4177 srgb(11,65,119)
96: ( 11, 65,119) #0B4177 srgb(11,65,119)
97: (167,167,167) #A7A7A7 srgb(167,167,167)
98: (167,167,167) #A7A7A7 srgb(167,167,167)
99: (167,167,167) #A7A7A7 srgb(167,167,167)
100: ( 11, 65,119) #0B4177 srgb(11,65,119)
101: ( 11, 65,119) #0B4177 srgb(11,65,119)
102: (167,167,167) #A7A7A7 srgb(167,167,167)
103: ( 11, 65,119) #0B4177 srgb(11,65,119)
104: ( 11, 65,119) #0B4177 srgb(11,65,119)
105: (255,167, 2) #FFA702 srgb(255,167,2)
106: (255,167, 2) #FFA702 srgb(255,167,2)
107: ( 11, 65,119) #0B4177 srgb(11,65,119)
108: (255,167, 2) #FFA702 srgb(255,167,2)
109: ( 11, 65,119) #0B4177 srgb(11,65,119)
110: ( 11, 65,119) #0B4177 srgb(11,65,119)
111: ( 48,233, 9) #30E909 srgb(48,233,9)
112: ( 11, 65,119) #0B4177 srgb(11,65,119)
113: ( 11, 65,119) #0B4177 srgb(11,65,119)
114: (167,167,167) #A7A7A7 srgb(167,167,167)
115: (167,167,167) #A7A7A7 srgb(167,167,167)
116: ( 11, 65,119) #0B4177 srgb(11,65,119)
117: (167,167,167) #A7A7A7 srgb(167,167,167)
118: (167,167,167) #A7A7A7 srgb(167,167,167)
119: (167,167,167) #A7A7A7 srgb(167,167,167)
120: (167,167,167) #A7A7A7 srgb(167,167,167)
121: ( 11, 65,119) #0B4177 srgb(11,65,119)
122: (255,167, 2) #FFA702 srgb(255,167,2)
123: ( 11, 65,119) #0B4177 srgb(11,65,119)
124: (255,167, 2) #FFA702 srgb(255,167,2)
125: ( 11, 65,119) #0B4177 srgb(11,65,119)
126: ( 11, 65,119) #0B4177 srgb(11,65,119)
127: ( 11, 65,119) #0B4177 srgb(11,65,119)
128: ( 11, 65,119) #0B4177 srgb(11,65,119)
129: ( 0, 0, 0) #000000 black
130: ( 11, 65,119) #0B4177 srgb(11,65,119)
131: (167,167,167) #A7A7A7 srgb(167,167,167)
132: (167,167,167) #A7A7A7 srgb(167,167,167)
133: (167,167,167) #A7A7A7 srgb(167,167,167)
134: (167,167,167) #A7A7A7 srgb(167,167,167)
135: ( 11, 65,119) #0B4177 srgb(11,65,119)
136: (167,167,167) #A7A7A7 srgb(167,167,167)
137: ( 11, 65,119) #0B4177 srgb(11,65,119)
138: (255,167, 2) #FFA702 srgb(255,167,2)
139: ( 11, 65,119) #0B4177 srgb(11,65,119)
140: (255,167, 2) #FFA702 srgb(255,167,2)
141: (255,167, 2) #FFA702 srgb(255,167,2)
142: (255,167, 2) #FFA702 srgb(255,167,2)
143: (255,167, 2) #FFA702 srgb(255,167,2)
144: ( 11, 65,119) #0B4177 srgb(11,65,119)
145: ( 0, 0, 0) #000000 black
146: ( 11, 65,119) #0B4177 srgb(11,65,119)
147: (167,167,167) #A7A7A7 srgb(167,167,167)
148: ( 11, 65,119) #0B4177 srgb(11,65,119)
149: ( 11, 65,119) #0B4177 srgb(11,65,119)
150: (167,167,167) #A7A7A7 srgb(167,167,167)
151: ( 11, 65,119) #0B4177 srgb(11,65,119)
152: (167,167,167) #A7A7A7 srgb(167,167,167)
153: ( 11, 65,119) #0B4177 srgb(11,65,119)
154: ( 11, 65,119) #0B4177 srgb(11,65,119)
155: (255,167, 2) #FFA702 srgb(255,167,2)
156: ( 11, 65,119) #0B4177 srgb(11,65,119)
157: (255,167, 2) #FFA702 srgb(255,167,2)
158: ( 11, 65,119) #0B4177 srgb(11,65,119)
159: ( 11, 65,119) #0B4177 srgb(11,65,119)
160: ( 11, 65,119) #0B4177 srgb(11,65,119)
161: ( 0, 0, 0) #000000 black
162: ( 11, 65,119) #0B4177 srgb(11,65,119)
163: (167,167,167) #A7A7A7 srgb(167,167,167)
164: (167,167,167) #A7A7A7 srgb(167,167,167)
165: ( 11, 65,119) #0B4177 srgb(11,65,119)
166: (167,167,167) #A7A7A7 srgb(167,167,167)
167: (167,167,167) #A7A7A7 srgb(167,167,167)
168: ( 11, 65,119) #0B4177 srgb(11,65,119)
169: (255, 43, 13) #FF2B0D srgb(255,43,13)
170: (255, 43, 13) #FF2B0D srgb(255,43,13)
171: ( 11, 65,119) #0B4177 srgb(11,65,119)
172: (255,167, 2) #FFA702 srgb(255,167,2)
173: (255,167, 2) #FFA702 srgb(255,167,2)
174: ( 11, 65,119) #0B4177 srgb(11,65,119)
175: ( 2,161,255) #02A1FF srgb(2,161,255)
176: ( 11, 65,119) #0B4177 srgb(11,65,119)
177: ( 11, 65,119) #0B4177 srgb(11,65,119)
178: ( 11, 65,119) #0B4177 srgb(11,65,119)
179: (167,167,167) #A7A7A7 srgb(167,167,167)
180: (167,167,167) #A7A7A7 srgb(167,167,167)
181: ( 11, 65,119) #0B4177 srgb(11,65,119)
182: (167,167,167) #A7A7A7 srgb(167,167,167)
183: ( 11, 65,119) #0B4177 srgb(11,65,119)
184: ( 11, 65,119) #0B4177 srgb(11,65,119)
185: ( 11, 65,119) #0B4177 srgb(11,65,119)
186: (255, 43, 13) #FF2B0D srgb(255,43,13)
187: ( 11, 65,119) #0B4177 srgb(11,65,119)
188: (255,167, 2) #FFA702 srgb(255,167,2)
189: ( 11, 65,119) #0B4177 srgb(11,65,119)
190: ( 2,161,255) #02A1FF srgb(2,161,255)
191: ( 11, 65,119) #0B4177 srgb(11,65,119)
192: ( 11, 65,119) #0B4177 srgb(11,65,119)
193: (167,167,167) #A7A7A7 srgb(167,167,167)
194: (167,167,167) #A7A7A7 srgb(167,167,167)
195: (167,167,167) #A7A7A7 srgb(167,167,167)
196: ( 11, 65,119) #0B4177 srgb(11,65,119)
197: (167,167,167) #A7A7A7 srgb(167,167,167)
198: (167,167,167) #A7A7A7 srgb(167,167,167)
199: ( 11, 65,119) #0B4177 srgb(11,65,119)
200: ( 11, 65,119) #0B4177 srgb(11,65,119)
201: (255, 43, 13) #FF2B0D srgb(255,43,13)
202: (255, 43, 13) #FF2B0D srgb(255,43,13)
203: (255, 43, 13) #FF2B0D srgb(255,43,13)
204: ( 11, 65,119) #0B4177 srgb(11,65,119)
205: (119, 85,255) #7755FF srgb(119,85,255)
206: ( 11, 65,119) #0B4177 srgb(11,65,119)
207: ( 2,161,255) #02A1FF srgb(2,161,255)
208: ( 11, 65,119) #0B4177 srgb(11,65,119)
209: ( 11, 65,119) #0B4177 srgb(11,65,119)
210: ( 11, 65,119) #0B4177 srgb(11,65,119)
211: (167,167,167) #A7A7A7 srgb(167,167,167)
212: ( 11, 65,119) #0B4177 srgb(11,65,119)
213: (167,167,167) #A7A7A7 srgb(167,167,167)
214: ( 11, 65,119) #0B4177 srgb(11,65,119)
215: ( 11, 65,119) #0B4177 srgb(11,65,119)
216: ( 11, 65,119) #0B4177 srgb(11,65,119)
217: (255, 43, 13) #FF2B0D srgb(255,43,13)
218: ( 11, 65,119) #0B4177 srgb(11,65,119)
219: ( 11, 65,119) #0B4177 srgb(11,65,119)
220: (119, 85,255) #7755FF srgb(119,85,255)
221: ( 11, 65,119) #0B4177 srgb(11,65,119)
222: (119, 85,255) #7755FF srgb(119,85,255)
223: ( 11, 65,119) #0B4177 srgb(11,65,119)
224: ( 11, 65,119) #0B4177 srgb(11,65,119)
225: (255,178,255) #FFB2FF srgb(255,178,255)
226: (255,178,255) #FFB2FF srgb(255,178,255)
227: ( 11, 65,119) #0B4177 srgb(11,65,119)
228: ( 0, 0, 0) #000000 black
229: ( 11, 65,119) #0B4177 srgb(11,65,119)
230: ( 11, 65,119) #0B4177 srgb(11,65,119)
231: (255, 43, 13) #FF2B0D srgb(255,43,13)
232: (255, 43, 13) #FF2B0D srgb(255,43,13)
233: ( 11, 65,119) #0B4177 srgb(11,65,119)
234: (255, 43, 13) #FF2B0D srgb(255,43,13)
235: ( 11, 65,119) #0B4177 srgb(11,65,119)
236: ( 11, 65,119) #0B4177 srgb(11,65,119)
237: (119, 85,255) #7755FF srgb(119,85,255)
238: ( 11, 65,119) #0B4177 srgb(11,65,119)
239: (119, 85,255) #7755FF srgb(119,85,255)
240: ( 11, 65,119) #0B4177 srgb(11,65,119)
241: ( 11, 65,119) #0B4177 srgb(11,65,119)
242: ( 11, 65,119) #0B4177 srgb(11,65,119)
243: ( 11, 65,119) #0B4177 srgb(11,65,119)
244: ( 11, 65,119) #0B4177 srgb(11,65,119)
245: ( 11, 65,119) #0B4177 srgb(11,65,119)
246: ( 11, 65,119) #0B4177 srgb(11,65,119)
247: ( 11, 65,119) #0B4177 srgb(11,65,119)
248: ( 11, 65,119) #0B4177 srgb(11,65,119)
249: ( 11, 65,119) #0B4177 srgb(11,65,119)
250: ( 11, 65,119) #0B4177 srgb(11,65,119)
251: ( 11, 65,119) #0B4177 srgb(11,65,119)
252: ( 11, 65,119) #0B4177 srgb(11,65,119)
253: ( 11, 65,119) #0B4177 srgb(11,65,119)
254: ( 11, 65,119) #0B4177 srgb(11,65,119)
255: ( 11, 65,119) #0B4177 srgb(11,65,119)
Rendering intent: Perceptual
Gamma: 0.454545
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Background color: white
Border color: srgb(223,223,223)
Matte color: grey74
Transparent color: black
Interlace: None
Intensity: Undefined
Compose: Over
Page geometry: 2880x1800+0+0
Dispose: Undefined
Iterations: 0
Compression: Zip
Orientation: Undefined
Properties:
date:create: 2016-10-25T01:52:33+09:00
date:modify: 2016-10-25T01:52:40+09:00
png:IHDR.bit-depth-orig: 8
png:IHDR.bit_depth: 8
png:IHDR.color-type-orig: 3
png:IHDR.color_type: 3 (Indexed)
png:IHDR.interlace_method: 0 (Not interlaced)
png:IHDR.width,height: 2880, 1800
png:PLTE.number_colors: 256
png:sRGB: intent=0 (Perceptual Intent)
signature: eab3dc5d88e3b079b92e5bd9303efee2745deef5ed2434fc3943200cfec6659a
Artifacts:
filename: nyan-task.png
verbose: true
Tainted: False
Filesize: 13.1KB
Number pixels: 5.184M
Pixels per second: 178.8MB
User time: 0.016u
Elapsed time: 0:01.029
Version: ImageMagick 6.9.3-5 Q16 x64 2016-02-20 http://www.imagemagick.org
この256個の色を16x16に並べるとDataMatrixのパターンが現れる。
読み取ると u.to/P4JUBg という文字列が降ってくる。
URLとしてアクセスするとフラグが降ってくる。終わり。
$ curl -i u.to/P4JUBg
HTTP/1.1 302 Found
Server: uServ/1.5.1
Date: Fri, 28 Oct 2016 10:39:09 GMT
Content-Type: text/html; charset=iso-8859-1
Transfer-Encoding: chunked
Connection: keep-alive
Keep-Alive: timeout=15
Set-Cookie: lng=en; path=/; expires=Sat, 28-Oct-2017 10:39:09 GMT; domain=.u.to;
Location: https://www.google.ru/search?q=RUCTF_ca8250c2b4b50581afc9ffd1f403f3f2
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<HTML><HEAD>
<TITLE>302 Found</TITLE>
</HEAD><BODY>
<H1>Found</H1>
The document has moved <A HREF="https://www.google.ru/search?q=RUCTF_ca8250c2b4b50581afc9ffd1f403f3f2">here</A>.<P>
</BODY></HTML>
ちなみにカラーテーブルが256なら16x16に並べるのは常識。
