CTF Midnight Flag : Крузенштерн

We start the challenge with an output.txt file:

!AIVDO,1,1,,A,144UN=000053CHTAqjKHT@000000,0*27
!AIVDO,1,1,,A,144UN=000054s6:At<s8T@000000,0*1B
!AIVDO,1,1,,A,144UN=000054;drB7Mq`T@000000,0*22
!AIVDO,1,1,,A,144UN=000054nqRBAQ`HT@000000,0*11
!AIVDO,1,1,,A,144UN=000053A?pBBE88T@000000,0*6A
!AIVDO,1,1,,A,144UN=000054otdBj7D8T@000000,0*3A
!AIVDO,1,1,,A,144UN=000054otdBJH78T@000000,0*16
!AIVDO,1,1,,A,144UN=000053@;PBIvGHT@000000,0*78
!AIVDO,1,1,,A,144UN=000053?78BkDT8T@000000,0*10
!AIVDO,1,1,,A,144UN=0000539i4C;MQ8T@000000,0*19
!AIVDO,1,1,,A,144UN=000054t9BC<A0pT@000000,0*57
!AIVDO,1,1,,A,144UN=000054s6:Bruk8T@000000,0*4F
!AIVDO,1,1,,A,144UN=000054v?NCQwN8T@000000,0*32
!AIVDO,1,1,,A,144UN=000054nqRD7J9HT@000000,0*23
!AIVDO,1,1,,A,144UN=000054pwnCbL=8T@000000,0*27
!AIVDO,1,1,,A,144UN=0000547N6Cc?dpT@000000,0*62
!AIVDO,1,1,,A,144UN=0000547N6CttbpT@000000,0*38
!AIVDO,1,1,,A,144UN=0000546JFCbL=8T@000000,0*74
!AIVDO,1,1,,A,144UN=0000532AbCbL=8T@000000,0*58
!AIVDO,1,1,,A,144UN=000054pwnDS:mpT@000000,0*7F
!AIVDO,1,1,,A,144UN=000054otdDGP7HT@000000,0*75
!AIVDO,1,1,,A,144UN=000053ut2DPhF8T@000000,0*10
!AIVDO,1,1,,A,144UN=000053slDDGP7HT@000000,0*56
!AIVDO,1,1,,A,144UN=000053h94DQSn8T@000000,0*54
!AIVDO,1,1,,A,144UN=000052qe0DEq7`T@000000,0*23
!AIVDO,1,1,,A,144UN=000052p`HDUUE`T@000000,0*19
!AIVDO,1,1,,A,144UN=000052oSfDfmTHT@000000,0*29
!AIVDO,1,1,,A,144UN=000054lk8DwEBHT@000000,0*65
!AIVDO,1,1,,A,144UN=000052nO4E@`P8T@000000,0*38
!AIVDO,1,1,,A,144UN=000053du0E8wA8T@000000,0*73
!AIVDO,1,1,,A,144UN=000053g54DnNkHT@000000,0*00
!AIVDO,1,1,,A,144UN=000054kgtES8upT@000000,0*75
!AIVDO,1,1,,A,144UN=000052kA0ES8upT@000000,0*11
!AIVDO,1,1,,A,144UN=000054fOdF=H``T@000000,0*58
!AIVDO,1,1,,A,144UN=000054gRvEg=LHT@000000,0*7E
!AIVDO,1,1,,A,144UN=000053rhLEhlL8T@000000,0*42
!AIVDO,1,1,,A,144UN=000053nPnF>UpHT@000000,0*64
!AIVDO,1,1,,A,144UN=000052dlTF=H``T@000000,0*4F
!AIVDO,1,1,,A,144UN=000052fv6Ek>spT@000000,0*15
!AIVDO,1,1,,A,144UN=000052bbvFI3G8T@000000,0*15
!AIVDO,1,1,,A,144UN=000052`QFFv4BHT@000000,0*59
!AIVDO,1,1,,A,144UN=000054ejhGf;KpT@000000,0*60
!AIVDO,1,1,,A,144UN=000054iwlG<HP8T@000000,0*0F
!AIVDO,1,1,,A,144UN=000053osDG;U08T@000000,0*58
!AIVDO,1,1,,A,144UN=000053noJGeGspT@000000,0*0C
!AIVDO,1,1,,A,144UN=000052gDtGd:d8T@000000,0*32
!AIVDO,1,1,,A,144UN=000052gDtG:iP8T@000000,0*0B
!AIVDO,1,1,,A,144UN=000054b`nHL2mpT@000000,0*61
!AIVDO,1,1,,A,144UN=000054ejhGtbIpT@000000,0*29
!AIVDO,1,1,,A,144UN=000053gK`Gs3J8T@000000,0*18
!AIVDO,1,1,,A,144UN=000053fG`HAUGHT@000000,0*33
!AIVDO,1,1,,A,144UN=000053d?TGsnr8T@000000,0*3E
!AIVDO,1,1,,A,144UN=000052c1lGsnr8T@000000,0*0E
!AIVDO,1,1,,A,144UN=000052au2HHlnHT@000000,0*4C
!AIVDO,1,1,,A,144UN=000054aURI5ph`T@000000,0*44
!AIVDO,1,1,,A,144UN=000054aURHWeT`T@000000,0*0E
!AIVDO,1,1,,A,144UN=000052`p<HV6T`T@000000,0*10
!AIVDO,1,1,,A,144UN=000052VfRI34Q8T@000000,0*65
!AIVDO,1,1,,A,144UN=000052RK2IDGfpT@000000,0*57
!AIVDO,1,1,,A,144UN=000054dgNIDiNpT@000000,0*31
!AIVDO,1,1,,A,144UN=000054`R<IlSbpT@000000,0*4C
!AIVDO,1,1,,A,144UN=000053gK`IigK8T@000000,0*59
!AIVDO,1,1,,A,144UN=000053eCVIFj>`T@000000,0*6A
!AIVDO,1,1,,A,144UN=000052SOrIgfcHT@000000,0*2D
!AIVDO,1,1,,A,144UN=000054TDdJKw5pT@000000,0*61
!AIVDO,1,1,,A,144UN=000054aURIwJqHT@000000,0*0D
!AIVDO,1,1,,A,144UN=000053TjtIwlaHT@000000,0*10
!AIVDO,1,1,,A,144UN=000053TjtJLHmpT@000000,0*38
!AIVDO,1,1,,A,144UN=000053RbbJ11q8T@000000,0*70
!AIVDO,1,1,,A,144UN=000052HfLIwJqHT@000000,0*0F
!AIVDO,1,1,,A,144UN=000052DJBJNkEHT@000000,0*0E
!AIVDO,1,1,,A,144UN=000052?v:Jlk>`T@000000,0*40
!AIVDO,1,1,,A,144UN=000054T=8Jo=fHT@000000,0*41
!AIVDO,1,1,,A,144UN=000054WG@JPB1HT@000000,0*57
!AIVDO,1,1,,A,144UN=000054S9fK>S;HT@000000,0*7F
!AIVDO,1,1,,A,144UN=000052<fhK8rd8T@000000,0*4F
!AIVDO,1,1,,A,144UN=0000529O@Kcro`T@000000,0*43
!AIVDO,1,1,,A,144UN=0000529O@KkT6pT@000000,0*24
!AIVDO,1,1,,A,144UN=000054Lm2KpI68T@000000,0*49
!AIVDO,1,1,,A,144UN=000053FlPL6p4HT@000000,0*2D
!AIVDO,1,1,,A,144UN=000054KiTLBRjpT@000000,0*16
!AIVDO,1,1,,A,144UN=0000521r`LAgBpT@000000,0*5B
!AIVDO,1,1,,A,144UN=000054ELHLhew8T@000000,0*69
!AIVDO,1,1,,A,144UN=000054HW0LKk1`T@000000,0*34
!AIVDO,1,1,,A,144UN=0000537o<LKIA`T@000000,0*2A
!AIVDO,1,1,,A,144UN=0000532PdLmRvHT@000000,0*6A
!AIVDO,1,1,,A,144UN=0000536jfLKk1`T@000000,0*26
!AIVDO,1,1,,A,144UN=000051rEJLJ<1pT@000000,0*25
!AIVDO,1,1,,A,144UN=000051q@2LnFNHT@000000,0*42
!AIVDO,1,1,,A,144UN=000054<wLMEE:HT@000000,0*1E
!AIVDO,1,1,,A,144UN=000054DHjLvIMHT@000000,0*36
!AIVDO,1,1,,A,144UN=0000533U>Lw<u8T@000000,0*33
!AIVDO,1,1,,A,144UN=000052qt6MNw98T@000000,0*66
!AIVDO,1,1,,A,144UN=000051eD:MJua`T@000000,0*4B
!AIVDO,1,1,,A,144UN=000051lrLLtHe`T@000000,0*04
!AIVDO,1,1,,A,144UN=0000546r:N1HdpT@000000,0*7B
!AIVDO,1,1,,A,144UN=000054;90M`L@8T@000000,0*0D
!AIVDO,1,1,,A,144UN=000052lmvMW?08T@000000,0*7A
!AIVDO,1,1,,A,144UN=000052kiBN7ld8T@000000,0*29
!AIVDO,1,1,,A,144UN=000051MANN5ktHT@000000,0*4D
!AIVDO,1,1,,A,144UN=000051UvbMV1hHT@000000,0*68
!AIVDO,1,1,,A,144UN=0000548`FN??Q8T@000000,0*1F
!AIVDO,1,1,,A,144UN=0000548`FNRSN`T@000000,0*59
!AIVDO,1,1,,A,144UN=000052w:`NHOgpT@000000,0*53
!AIVDO,1,1,,A,144UN=000052obFN`UepT@000000,0*05
!AIVDO,1,1,,A,144UN=000052S?dNJPO`T@000000,0*53
!AIVDO,1,1,,A,144UN=000051Jd2Nc0=`T@000000,0*7F
!AIVDO,1,1,,A,144UN=000051KihNFO08T@000000,0*26

With some research, I gather the following information:

Крузенштерн is a four-masted barque ship belonging to the Soviet fleet.
The AIVDO data is issued by an automatic identification system (AIS) for ships to report their position.

With this information, I guess we will have to retrieve the GPS coordinates from the file.

I go to the site https://www.maritec.co.za/aisvdmvdodecoding to decode the AIVDO data.

Extract from the output below:

1,0,273243700,0,+0.0,0.0,0,70.6265900,E,31.2876483,N,219.3,0,0,0,0,0
1,0,273243700,0,+0.0,0.0,0,70.9805950,E,31.3535667,N,219.3,0,0,0,0,0
1,0,273243700,0,+0.0,0.0,0,70.8188217,E,31.6611833,N,219.3,0,0,0,0,0
...

I format my output to get only the GPS coordinates in the format: longitude,latitude

70.6265900,31.2876483
70.9805950,31.3535667
70.8188217,31.6611833
...

And finally, I go to the following site https://www.gpsvisualizer.com/map_input allowing to inject all my GPS coordinates in order to retrace the route:

misc

Flag: MCTF{AIS_SECRET_MESS}