I'm not sure is this correct, but it sounds like that...
Riff 1 A
|-------------------|
|-------------------|
|-------------------| 4x
|-------------------|
|--4-----4---5------|
|--2-2-2---2---2-2--|
* * * * *
Riff 1 B
|-------------------|
|-------------------|
|-------------------| 4x
|------------2------|
|--2-----2----------|
|--0-0-0---0---0-0--|
* * * * *
Riff 2
|-----------------------------------------------------------|
|-----------------------------------------------------------|
|-----------------------------------------------------------|
|------------------------2---------------------------4--5---|
|----4-----4-----4-------0--2------4-----4-----4-----2--3---|
|--0-2--00-2---0-2--00------0----0-2--00-2---0-2--00--------|
* ** * ** * ** * **
[ Tab from: https://www.guitartabs.cc/tabs/a/anthrax/medusa_tab_ver_4.html ]
Riff 3 2nd time dont play this
----------
|---------------------------------------------------------------------|
|---------------------------------------------------------------------|
|---------------------------------------------------------------------|
|---------6-----------------------------------------------------------|
|--7--777----7-6-5---------6---------------4---------------6----------|
|-------------------7--777----7-6-5--5-555----5-4-3--7-777----5-6-7---|
When you play Riff 3 Second time, don't do this part on the end
|----------------|
|----------------|
|----------------|
|----------------|
|-6--------------|
|----5-6-7-------|
Riff 4
|----------------------------------------|
|----------------------------------------|
|----------------------------------------|
|----------2-----------------------------|
|--4--4-4--0--4--3--4--X-XXX-XXX-XXX-XX--|
|--2--2-2-----2--1--2--X-XXX-XXX-XXX-XX--|
Outro
|---------------------|
|---------------------|
|---------------------|
|----------2----------|
|--4--4-4--0--4--3--4-|
|--2--2-2-----2--1--2-|
ORDER
-----
Riff 1 A+B 4x
Riff 2 2x
Riff 1 A+B 2x
Riff 2 2x
Riff 3 2x
Riff 4 4x
Riff 1 A+B 2x
Riff 2 2x
Riff 3 2x
Riff 4 7x (with solo, solo is coming soon!)
Riff 2 4x (with solo)
Riff 1 A+B 2x
Riff 2 2x
Riff 4 4x
Outro 4x