There are 3 variants in this version:
When the virus is run, it infects first 3 uninfected DOS and EXE executable in the current directory, i.e. 6 files are infected on each run.
The virus does not infect COMMAND.COM and files that are smaller than 600 bytes.
The virus activates when the minute is equal to 30, and the second is less than or equal to 30. It displays a high quality payload of a Mars-esque surface scrolling by and captions. For its time, it was considered to be a high quality modeling, but by today's standards, this is considered to be low quality.
Spanska.1474 displays the caption:
SPANSKA PresentMars L Mars Landing|μ♥ *.* *.C* *.E* .
The later part of the caption (containing garbage letters and filename extensions) is expected not to be shown.
Spanska.1500 and 1509 are the bug fixing releases since Spanska.1474, they display the caption:
Mars Land, by Spanska (coding a virus can be creative)
The virus contains the internal text string:
*.* *.C* *.E*
Description of Spanska, F-Secure Lab