[ReverseMe]Shiftr
Wassup everyone! I’ve got another simple ReverseMe. This time, you’ll need to decipher(mhmm) and transform. There’s a hidden seed and a couple of tricks. Difficulty? I’d say it’s intermediate, Nah, it’s pretty simple.
The idea is to try to understand what the challenge is about and figure out how it operates. Don’t take shortcuts! 😉 This is something I wrote without much attention, so not much testing has been done. Here’s your warning: make sure you’re on x64, and remember, not everything is as it seems or is it? Who knows!
Executable
H4sIAN8xKWcC/+1cf3iT1b0/b9KUWqBJhU4GKC8TXDslpgiuCJUGGnnZCpYfueoVDKFJaGZIuuSN
FB+Z1VjHa4nrvNdNd9nz1GePu+id0z13Ux6u0oQircztpuq83TOnVXELAq4gYlXkvd9z3nPSk2Mj
Pj7bH/e5OZh838/nfL/nx/ec8z2nMSd3upquM0kSYsmMrkUYNUwxcAPlm505FeDq0GR4vxjNRKWA
Szg9UQ6Z8mVZrh7DbprZwKKcifKlxMkSVDgpk/Ilso3ZWTgsygcr8yVvR+pzUF6UJYLk7LBvRpYY
eKQpX1bTfm4y59uZqB2qp/wqQZryZRlXPX7V0fJEKaN8KdrdSPVE2YjyJevmundU35epr5naHaH+
E+VulC9ZfWvArhR98cSGdy2tr9A42Mz5ks2zK0PBzVcvuDLkmxcKhuPt89rrrp539QJ7LGKfn2uX
jc6pFavdeDhSJXRes/ypFOP8O5+eg0Yqn9iTcAzc+bhc/f1bLpUuYWVIVIetCxPXD4wv5uYTkh5B
HZLNhLlZVKf64l0zB/2/3xpwe22LTnXN/Dy/PAqvC8fh7y7AT+LGkE/3FdD/zwJ8qgD/rwX4K6Tx
+W8U4P+7QDnTCujfUUB/XwG+vwBvK1B+dQG//aBAOZ4CfFsBfk0BflsB/uMC/DcLtPOmAvqnC/A7
CvCvF+DfL8D/D7wq0XQkN+fHDbxFfW0c/SeovkPQP075BoFHsK59IWMde1auX+Xx+aP+LcGY6o+u
X7U8FAn713s3h/zI49myNRL2xFRvVPV4DNVxFX2hllAkhmVs+1Z4j7T5w7iSFlzH1SgQCMVjrcjf
HlRRLOoN+1BMjYZb2rajtrgaQ2pwK64Lqmm51dPSeqsn4A2GcFZLqzcKqr5gGG3xq21BHwqAjGHr
kJ9wVCPaEmsLY81IXIWSWtTtbX7PZk8o0oJJfzSK4rGQ39+GAtuiQRVX1tLu9QSCYW8oeLsfxbbH
WryhENC4zbS/W71QbSzcFg2G1QBa0bRy2XLPfPt8+8Lc81W5pwXGZmSi7yaIWCbhH84poS8TiY1Y
WvI0JPLPiId4PsanBy/AmldJLC6bUYCL61OCwck4+i6VDG4qwWa0kmLD3pSzZ/GezQN5qiFHBX6Y
nnvKhHnDsE3k6b41dL0hS7k9gJTH8RM5PsvxNo4f4fiLOH6U4y/heLZOLHSfYMnB8bM4voHj+XU/
jZY/gdsDSfkcz+9L1RzPn8ccHG/h+DqO5/fxBo6fwJ/jOL6M45s5/gKOv5Hjyzl+E8dP4vhWjp/M
x1uOr+D4do63cnwHx1dy/E6O5+NcN8dP4fiHOH4qx/dwfBXH7+H4r3D8Uxw/jeP3cvxX+X2Z46dz
/ADHz+D4DMfPRMVUTMX0fzm9b73kYyVxvEzpsvxxKYTdzpRq0jNK4mBZH8nXF751LUKn9Llvg7DO
IvqtOOPU0Td1Xe8mWCJ4MIdNBKdz2Ezwr3K4hOBHcthC8A9zuJTgu3J4AsHfzeEygr05fAHBa3K4
nGBnDk8kuDaHJxE8O4cnE1yZwxUESzlsJfjkOYZtRv9zuNLofw5faPQ/h6cY/c/hqUb/c7jK6H8O
f8Xofw5fZPSfYRiNejIajcb4AV5Vn49dAq4X8EIBzxPwXAFfLOAqAU8WsEXAny7Jxx8I+ISA3xHw
nwX8BwH/TsDPC/g5Af9GwE8I+FEB/1TAD/K49sRKbfAWRXtLSRwZaV7flLRcBjNISU5+cjIW9VfB
fNSromByuhvgI0swa/kJFotG1SpYequXGEvvAn3YOqsDL68+KkH/u0R/4XewqDmnaCNK+r2lSnrU
rEiHlMFz6lQoYC4toEwfDpB2MXvcvo76jfjTj/jlbiVRb8KPivaOOknpqi8FkH3sU13P+mCyH7Is
BCxtBNs8+6PbIBM/uMEOgoVN0XaMKl2uUUXrz/4XWCvaAQMOwtN+HA168dtectCdjqftC33Mvjv7
EVgkRsvjZ7q7N+bodVBuNXjlxzNw61zD8PiI8Zjtd5EPD3tJaa+BsdaXXQiidgiq34UbvwKqePjD
HUOa+7Uu12vKQ0pX4/PDinYInBedwdoxHzT7Xa/g52NfB5d9bTEuvj/7OPC9w/9SgrIyFNNrx7o/
PwtNdL0iJXa8Yvrey704nmQfAK4bAmP1zWOtdq7H7d4E/tijaPEezb3bp3SVzK1GRstrU0rXqj1K
0pXZZyPU73GFN0FBh1zDSOl3DeDWHP0pxEfw34B2oMu1W8okhmdprhQ8Kl3uASVxwKxYnzygaGll
3+9eNJKiDSgfvqWk3zUrWkZJD5sUKaNIKaUmrWiHNfdBJenO4AKBtj6Ndrp6ib+ULqRY97t7Fekl
nPEMsj6TmosP750p6z0RyWhDYliCeWTtTOMu62cLWZmwlVrmfNaL3VnqfBZ/PGzdv7E3+9vz2EzY
S0wse7FFTZ82hHudkjJkCvUol0Ork5NMyr7nVx8/iP/L7yt0UvpsjzON0jD4Z6zXO8uOLofqstee
vwO30w78M+tA+ZfpwEHpALQumLoetzidldNZ862p6TVAOmsONmqfad2j4O5szyeFaiozBuVVPGm6
Vg0o+/7jcSNRb0Bdg1m86rDVAUzWZGDY4k24KOLOpJLRDu/FE4bMHmiSdgB8qGXAd1JGStWksd/2
LcJ9gFaK7bNI2Buu3i73wcF3YUpmHeL4fLG5mEmkHGLZjxFP03YmsrO1NNSSKxy3VkrjUqGH+x7e
4Gz6pXzZDbTT6WyJcmvqFlL4QCI1Wyh6bAKrK7LzP4Y1PCyBVxbnrwdc3+4Co1U7IBaZcA1IBC12
9VjvdpPJ4e5Rkquwzh66pO8dJfQe0gspcwj+zoPHrE+5yggGqiX7M6ySOLjpZucGMX44IH4MQfzI
aO4XIShkSVD4OYxAF2Aohjj8CzhEcx2BRgwRE7ry384u/ig3yd4eZ5Kp1+GMLteRLzplkoqDq0Q7
vNN29AyOFS+PFqqHRpiHsdYTBbUKRZS3s9vPYzPugjxSeEEmJ5UIPTj2zTEnNL+hDe7dCE4GJ6QN
y1LwMLZMKrMFQ5gdWYngxa6M9e4mvNXhPcKRN8rG3kbH2NjGqj7EuybYgS1sZ4EzdDt7Dh6y7Tiz
BVr/0qzOY2tgacnaYPojy8M1g9rhW1/y1ZBYuQrbZpRkG65/yAmdTVbtnEq2NGO/W3vms/sVNETu
dx1tU6PeQL/rRIv/kOtviGzYsFWuB+vsrjOkYSNKYscIipeTfTz775hMuo9CTSOK9iqe8b829EZB
bzSndycm4SCwH7H9WsdTdKn16RSZm9i6P7sStMDXL3D+0XbAdh0f6nedJm3pcg83QaegqiatX6l9
4b7S+2bV9cXB3WnpnpR6oaIfUvT+Y1nI2kf2c8s+bKe5T3e5TgvdhbIhUsaHYWGNEt2rs9OgAQ+n
352G10gKvHkIKsySAwxmyjhUe5KO8qhEmMWu4WiqmzvNwDni8HzjHPHAafA3VzfUC1Va4Gx/rAps
08MWPC9HJXg7C7PHNWos7WZJ0dxZWKzW/eCks4kdZ1E8A3r89LnrOD4oiEeLpKWXDEKnomO3E6Fn
jMGfCDMRL7r78Lae7NwEOfvLkNFQPz4LGByG3wapdTZilLRcSuZl542Auh40OEOxK3kjV4Y+2N9Z
B5hEKiupo37WheykNfA+NqgarMW8q2O/j1Y8gnmIx+V78WgdjZqMfDjb/rXS0PglaBxqtHQYPBAb
sYnWxzcXM4v6brsCXH8nrkFL77sUimOz+GdQVLYUxsJoS+cHun6sjRXnOYdPj1xpq4FY1BeXe/H/
1cv+DZedrL8HF9F3ihZx9DCUnCDdlfbiv2QvJ8/kdPmdStbnV0DdWASPQyGJ57CKyXr/ESjf6O09
44zEnz7JG4k0Ptt2Nhgj8cePyEg0k5FoyBuJ5ryRyI18f+cSNiQWY0h22VjzFp4iQ3KtQxiSjafy
huQNlBuS9TZDY8YpYUgOnxSHZO/JsSE5fqUxJFXckLihqGyM+TN7Chx0LKAkHyT2pFQSUk58gues
ejFYLMIWzpPM4v6z9OmYM0E6yQZiCRuIN62sp98+yQZi9ik8EEuMgXiPDQSOnLAvT2L78kTc+LsO
4gUGkYP8fe28oSlZ//LlCDn/aaX2qtO9UvvAud6pnXUryXkHgV7XVPMp/swk2/se2KY/Nauzav9E
/15q0k41ae81an916lPfUBJ9krLoz/F38ecpN290bnBudN7i9PQFAnbrrHtyn7/08Z/D5D55KaZi
KqZiKqZiKqZiKqZiKqZiKqZi+vsliX6rS5avlDd44CWXy9WyHLFHZLmmXJbla+Vb5CUgy5EzFA1u
aVXlkF/9ekze7N8SDM9Ga/2rXLK3pcXfpvp9V8hEYymaG0NzHXWh9rmO+T7uy5BzrpHZl7PWRyJy
KBLeMlteHZE3xwMBf1SO3OaPBkKRbXKrP+q3l6NgTA6qctTvDS2VV3tb0Q1RYjDXB00IqKAwVsj6
6HbZu8UbDAO7OtjiD22XfZGwf7ZM+jjDvPghZHwPa8kbuv4iyBeHdR1/l/U1kJMkhDa8peu/Bux6
W9fnAO4E2QhyN0gfyLVHdH0nyAeyuv4LkO3v6noGpOkYlAPyIZBTwZUnQdaBXHdc128EuRVkO8hn
QD4E8ooRXX8W5G6QJeax73pJt69FUrtNmjFpQlm3ZPD4+1U9b+r6lVihcQL5muAceOGvXLa+rutY
D1XYrquY9i3rxG1lHWjp9Gu+cdUc8jVZbL8BXhnoL//9Qsyr8BoAvoP7oh+uaxe8vgp+aMCEq8J2
r2n55NJt0CCa/wt4LYL8i/j81UY+djT2qwPyn+bzXQmzac+Yzgi8DuA6SjidFbvMiRKzowTUsM5U
aNfrf9H1v0if0XlVojp1kNcDY3GfWNcdY+3dADqlR3X9R7yOKUkUcBl3QP4dkH8Tn++EMq4fK6MH
dH4FOpvzyriJKOD8FOS/D/nT+fw1Y/bDkH8C8r+VZ+/MtQEvv4tgLqlmLl9JmM0tZqKD713MAZ3W
E7rux/rXVdh+YFpZMe1+s6tCTpa4Kqp3WRorHPeWKhV1iQkrKhrCFXXOCoezonpZhbysYtqyCtuy
ijLyHdMQlNMN5ViKYa+YiqmYiqmYiqmY/h8ldu+H3fPh7xXzMkBl7s4IPUSzuyI7ZxuS3aVg94vY
XQl2Z4XdqWD3jGYK+R+c0yNY9tBLQ+xsNkIvybC7MkM0n91tWUcbyu4UsbseVUJ/c3eR6L0Ndoen
wTT29wBO7O4Nu3NUVp7PZ8vy2y3T+i8Q6r9E6N8nutE/iVLnKN5JFXSKWbtGKG6k+R9RXPKPmhCr
xqcddLwbqGymchOVbVR2UNlNZQ+VT1GZojJD5TCVI+yPMnppyEalTKWDygYqm6ncRGUblR1UdlPZ
U/nl3JC770bvs61Yvvwaudq9OR5W4/Ii+wK7Y15tnKDa78132B0L7PNrDB4he6w1pkZV72ZkD4ZV
f7QN2cMR1W/fEo7b26KRNn9U3c5Rm+PBkG9e0Ecp57KV81TvFkTyWr2xVmT3bQ/jy5REqlEj5zZ/
NBaMhPOAB/Ki/pAXK9KntpCKWxGEd3i0b4nQh5i/BdlVfzvAAGSDdsTnVb3I7m/1BKLerX5Pqy86
howyPN5o1LvdsGDPUJV3axAKM8w3x2LI3hLZutUfVv8e03EijUFsPRT6XQQkxCuWpqD8u3qF7uUj
YZ2ydJlgL/4ewBxBX1yXiwT7O8z5Uj6P/Qp4nYE1z+xZXGRyAcqPi2L711AfmoS4OST4kd1zLBPi
100o/w4+i8NMrpM+3/9eGtOYPYtjTC4T2i/8nAMK0xjJMIuTTG7i4rVpnP7voD41CXGbSRa3Rf+x
/n+f2i8T9gEm2b5RSm1E+x8i7rcKuH2TyRnnGf9dgr1sy5fdgsPFn/P4sWD/VGW+tKHPt+8R7FOV
+bLjPPU/JtjnfkeFSlfF+PYsPSnYs3MGk5PP47/fCPFD/L2SN8+z/p8T7Av9Pkeh+n8r2HfUCtL0
+fX/ARn3bs3CuYr9fkdZgfYziftn5ezZuWv0C9qfQMIdbnY+qM9fqBMEOzaO/0b7L5670NLxA4ZY
/xnRvplNpPx1Vsh/ZynH7Nn98GkN+dMhdx4W9xPJqF/UY/aXF9h/eGkeZ19bTu3LzxM//xcEjVA7
kEgAAA==
As always, to recover the binary:
cat foo.txt | base64 -d | gunzip > foo.elf && chmod +x foo.elf
Enjoy !
^ ^ ^ ^ ^
/(\ /o\ /.\ /o\ /)\
<___> <___><___><___> <___>