Digital virus Ideas....

[KingS7ayer]

Here's what I'd do

USB => lan => wifi

wifi fans out into 3 sections

Torrents =>fake torrent review => exe modification
email scams =>instant messenger => email hack => blankbook+ hack
Ads => fake content => fake website mirror

Abilities
Secondary download => Code compression => Streamline code (reduced severity)
Manual upload (like trojan plans) => Auto upload (targets random countries)

basic AI (targets uninfect/least infective countries and has a minor mutation chance) => advanced AI (increased infection, reduced Severity and increased mutation chance) => Skynet (grants active ability to take control of all technology, maxes severity, increased lethality and increased mutation)

C#/C++ => Assembler => machine code/Binary (harder to cure)

Symptoms
Keylogger (increased severity, increased "DNA" from bubbles) => Spyware (increased severity, Increased "DNA" from bubbles)
malware (increased lethality) => File shift (increased lethality, moves random files, can cause blue screen) => anti-anti virus (focuses anti-virus destruction, increased severity, harder to cure)
Trojan (reduced severity) => System 32 (reduced severity) =>
Wyrm (increased infectivity) => fireproofing (gets past firewalls, increased infectivity) => Hydra ( increased infecivity)

Basically just stuff I remembered from my Computer Science course I did.

addition for achievements
Kill john connor - get the terminator reference pop up
phytohydra - get Hydra and anti-anti virus

This is just my input from ideas you gave me.

Also your english is better than most people I know.

Edit:
If anything needs explaining just ask. some of it may be a bit too technical I just wrote down what came to mind.