Function at 0x428020
Capabilities:
Check if file exists
Delete registry value
Persist via default file association registry key
Set registry value

Disassembly:
push ebp
mov ebp, esp
push 0xffffffffffffffff
push 0x581fd0
mov eax, dword fs:[0]
push eax
sub esp, 0x30
push ebx
push esi
push edi
mov eax, dword [0x6039b0]
xor eax, ebp
push eax
lea eax, [ebp - 0xc]
mov dword fs:[0], eax
mov edi, ecx
mov dword [ebp - 0x14], edi
mov dword [ebp - 4], 0
call fcn.00402a00
mov ecx, eax
test ecx, ecx
jne 0x428069
push 0x80004005
call fcn.00402a80
mov eax, dword [ecx]
call dword [eax + 0xc]
add eax, 0x10
mov dword [ebp - 0x24], eax
mov byte [ebp - 4], 1
or esi, 0xffffffff
mov eax, dword [ebp + 8]
cmp dword [eax - 0xc], 0
je 0x428092
lea eax, [ebp + 8]
push eax
lea ecx, [ebp - 0x24]
call fcn.00405c30
jmp 0x4280d4
lea ecx, [ebp - 0x2c]
call fcn.004268b0
push str.MasterOFD
mov byte [ebp - 4], 2
push dword [eax]
lea eax, [ebp - 0x24]
push str._s_s.exe
push eax
call fcn.004063c0
mov byte [ebp - 4], 1
add esp, 0x10
mov edx, dword [ebp - 0x2c]
mov eax, esi
add edx, 0xfffffff0
lock xadd dword [edx + 0xc], eax
dec eax
test eax, eax
jg 0x4280d4
mov ecx, dword [edx]
push edx
mov eax, dword [ecx]
call dword [eax + 4]
mov ebx, dword [ebp - 0x24]
push ebx
call dword [sym.imp.SHLWAPI.dll_PathFileExistsW]
test eax, eax
jne 0x4280e9
xor edi, edi
jmp 0x428597
push str.MasterOFD
lea ecx, [ebp - 0x20]
call fcn.00407740
lea eax, [ebp - 0x20]
mov byte [ebp - 4], 3
push eax
mov edx, str.SoftwareClasses_
lea ecx, [ebp - 0x18]
call fcn.0040d100
add esp, 4
mov byte [ebp - 4], 4
call fcn.00402a00
mov ecx, eax
test ecx, ecx
jne 0x428127
push 0x80004005
call fcn.00402a80
mov eax, dword [ecx]
call dword [eax + 0xc]
add eax, 0x10
mov dword [ebp - 0x2c], eax
push ecx
mov ecx, edi
mov byte [ebp - 4], 5
call fcn.00429c80
mov edx, eax
add esp, 4
test edx, edx
jne 0x42814b
xor ecx, ecx
jmp 0x42815f
mov ecx, edx
lea edi, [ecx + 2]
mov ax, word [ecx]
add ecx, 2
test ax, ax
jne 0x428150
sub ecx, edi
sar ecx, 1
push ecx
push edx
lea ecx, [ebp - 0x2c]
call fcn.00407ba0
mov edi, dword [ebp - 0x2c]
cmp dword [edi - 0xc], 0
je 0x4281bd
mov eax, dword [ebp - 0x20]
test eax, eax
jne 0x428183
push 0x80004005
call fcn.00402a80
push eax
push edi
call fcn.0055d308
add esp, 8
test eax, eax
je 0x4281bd
mov ecx, edi
lea edx, [ecx + 2]
mov ax, word [ecx]
add ecx, 2
test ax, ax
jne 0x428196
sub ecx, edx
sar ecx, 1
lea eax, [ecx + ecx]
push eax
push edi
push 1
push str.previous.pdf
push dword [ebp - 0x18]
push dword [ebp - 0x14]
call dword [sym.imp.SHLWAPI.dll_SHSetValueW]
push 0x18
push str.PDF_Document
push 1
push 0
push dword [ebp - 0x18]
push dword [ebp - 0x14]
call dword [sym.imp.SHLWAPI.dll_SHSetValueW]
call fcn.00402a00
mov ecx, eax
test ecx, ecx
jne 0x4281e9
push 0x80004005
call fcn.00402a80
mov eax, dword [ecx]
call dword [eax + 0xc]
add eax, 0x10
mov dword [ebp - 0x28], eax
push ebx
lea eax, [ebp - 0x28]
mov byte [ebp - 4], 6
push str._s_1
push eax
call fcn.004063c0
add esp, 0xc
lea edx, [ebp - 0x18]
lea ecx, [ebp - 0x34]
push str.DefaultIcon
call fcn.0040b270
add esp, 4
mov eax, dword [eax]
mov dword [ebp - 0x30], eax
mov eax, dword [ebp - 0x28]
mov edx, eax
lea ecx, [edx + 2]
mov dword [ebp - 0x1c], ecx
nop dword [eax]
mov cx, word [edx]
add edx, 2
test cx, cx
jne 0x428230
sub edx, dword [ebp - 0x1c]
sar edx, 1
lea ecx, [edx + edx]
push ecx
push eax
push 1
push 0
push dword [ebp - 0x30]
push dword [ebp - 0x14]
call dword [sym.imp.SHLWAPI.dll_SHSetValueW]
mov edx, dword [ebp - 0x34]
mov eax, esi
add edx, 0xfffffff0
lock xadd dword [edx + 0xc], eax
dec eax
test eax, eax
jg 0x42826f
mov ecx, dword [edx]
push edx
mov eax, dword [ecx]
call dword [eax + 4]
push str._shell
lea edx, [ebp - 0x18]
lea ecx, [ebp - 0x34]
call fcn.0040b270
add esp, 4
push 8
push str.open
push 1
push 0
push dword [eax]
push dword [ebp - 0x14]
call dword [sym.imp.SHLWAPI.dll_SHSetValueW]
mov edx, dword [ebp - 0x34]
mov eax, esi
add edx, 0xfffffff0
lock xadd dword [edx + 0xc], eax
dec eax
test eax, eax
jg 0x4282b2
mov ecx, dword [edx]
push edx
mov eax, dword [ecx]
call dword [eax + 4]
call fcn.00402a00
mov ecx, eax
test ecx, ecx
jne 0x4282c7
push 0x80004005
call fcn.00402a80
mov eax, dword [ecx]
call dword [eax + 0xc]
add eax, 0x10
mov dword [ebp - 0x1c], eax
push ebx
lea eax, [ebp - 0x1c]
mov byte [ebp - 4], 7
push str.__s_____1____
push eax
call fcn.004063c0
add esp, 0xc
lea edx, [ebp - 0x18]
lea ecx, [ebp - 0x38]
push str._shellopencommand
call fcn.0040b270
add esp, 4
mov eax, dword [eax]
mov dword [ebp - 0x30], eax
mov eax, dword [ebp - 0x1c]
mov edx, eax
lea ecx, [edx + 2]
mov dword [ebp - 0x34], ecx
nop dword [eax + eax]
mov cx, word [edx]
add edx, 2
test cx, cx
jne 0x428310
sub edx, dword [ebp - 0x34]
sar edx, 1
lea ecx, [edx + edx]
push ecx
push eax
push 1
push 0
push dword [ebp - 0x30]
push dword [ebp - 0x14]
call dword [sym.imp.SHLWAPI.dll_SHSetValueW]
mov edx, dword [ebp - 0x38]
test eax, eax
mov eax, esi
sete byte [ebp - 0xd]
add edx, 0xfffffff0
lock xadd dword [edx + 0xc], eax
dec eax
test eax, eax
jg 0x428355
mov ecx, dword [edx]
push edx
mov eax, dword [ecx]
call dword [eax + 4]
push ebx
lea eax, [ebp - 0x1c]
push str.__s___print_to_default____1_
push eax
call fcn.004063c0
add esp, 0xc
lea edx, [ebp - 0x18]
lea ecx, [ebp - 0x30]
push str._shellprintcommand
call fcn.0040b270
add esp, 4
mov eax, dword [eax]
mov dword [ebp - 0x34], eax
mov eax, dword [ebp - 0x1c]
mov edx, eax
lea ecx, [edx + 2]
mov dword [ebp - 0x38], ecx
nop word [eax + eax]
mov cx, word [edx]
add edx, 2
test cx, cx
jne 0x428390
sub edx, dword [ebp - 0x38]
sar edx, 1
lea ecx, [edx + edx]
push ecx
push eax
push 1
push 0
push dword [ebp - 0x34]
push dword [ebp - 0x14]
call dword [sym.imp.SHLWAPI.dll_SHSetValueW]
mov edx, dword [ebp - 0x30]
mov eax, esi
add edx, 0xfffffff0
lock xadd dword [edx + 0xc], eax
dec eax
test eax, eax
jg 0x4283cf
mov ecx, dword [edx]
push edx
mov eax, dword [ecx]
call dword [eax + 4]
push ebx
lea eax, [ebp - 0x1c]
push str.__s___print_to____2_____1_
push eax
call fcn.004063c0
add esp, 0xc
lea edx, [ebp - 0x18]
lea ecx, [ebp - 0x34]
push str._shellprinttocommand
call fcn.0040b270
mov esi, dword [ebp - 0x1c]
add esp, 4
mov ecx, esi
mov edx, dword [eax]
lea eax, [ecx + 2]
mov dword [ebp - 0x38], eax
mov ax, word [ecx]
add ecx, 2
test ax, ax
jne 0x428401
sub ecx, dword [ebp - 0x38]
sar ecx, 1
lea eax, [ecx + ecx]
push eax
push esi
push 1
push 0
push edx
push dword [ebp - 0x14]
call dword [sym.imp.SHLWAPI.dll_SHSetValueW]
mov edx, dword [ebp - 0x34]
or eax, 0xffffffff
add edx, 0xfffffff0
lock xadd dword [edx + 0xc], eax
dec eax
test eax, eax
jg 0x42843f
mov ecx, dword [edx]
push edx
mov eax, dword [ecx]
call dword [eax + 4]
cmp byte [ebp - 0xd], 0
je 0x4284fa
mov eax, dword [ebp - 0x20]
mov edx, eax
lea ecx, [edx + 2]
mov dword [ebp - 0x38], ecx
mov cx, word [edx]
add edx, 2
test cx, cx
jne 0x428454
sub edx, dword [ebp - 0x38]
sar edx, 1
lea ecx, [edx + edx]
push ecx
push eax
push 1
push 0
push str.SoftwareClasses.pdf
push dword [ebp - 0x14]
call dword [sym.imp.SHLWAPI.dll_SHSetValueW]
push 0
push 0x5dfc54
push 1
push dword [ebp - 0x20]
push str.SoftwareClasses.pdfOpenWithProgids
push dword [ebp - 0x14]
call dword [sym.imp.SHLWAPI.dll_SHSetValueW]
cmp dword [ebp - 0x14], 0x80000001
jne 0x4284f1
mov eax, dword [ebp - 0x20]
mov edx, eax
lea ecx, [edx + 2]
mov dword [ebp - 0x38], ecx
nop dword [eax]
mov cx, word [edx]
add edx, 2
test cx, cx
jne 0x4284b0
sub edx, dword [ebp - 0x38]
sar edx, 1
lea ecx, [edx + edx]
push ecx
push eax
push 1
push str.Progid
push str.SoftwareMicrosoftWindowsCurrentVersionExplorerFileExts.pdf
push reloc.WS2_32.dll_accept
call dword [sym.imp.SHLWAPI.dll_SHSetValueW]
push str.Application
push str.SoftwareMicrosoftWindowsCurrentVersionExplorerFileExts.pdf
push reloc.WS2_32.dll_accept
call dword [sym.imp.SHLWAPI.dll_SHDeleteValueW]
mov dword [ebp - 0x1c], 1
jmp 0x428501
mov dword [ebp - 0x1c], 0
lea edx, [esi - 0x10]
mov byte [ebp - 4], 6
or esi, 0xffffffff
mov eax, esi
lock xadd dword [edx + 0xc], eax
dec eax
test eax, eax
jg 0x42851f
mov ecx, dword [edx]
push edx
mov eax, dword [ecx]
call dword [eax + 4]
mov byte [ebp - 4], 5
mov eax, esi
mov edx, dword [ebp - 0x28]
add edx, 0xfffffff0
lock xadd dword [edx + 0xc], eax
dec eax
test eax, eax
jg 0x42853d
mov ecx, dword [edx]
push edx
mov eax, dword [ecx]
call dword [eax + 4]
mov byte [ebp - 4], 4
add edi, 0xfffffff0
mov eax, esi
lock xadd dword [edi + 0xc], eax
dec eax
test eax, eax
jg 0x428558
mov ecx, dword [edi]
push edi
mov eax, dword [ecx]
call dword [eax + 4]
mov byte [ebp - 4], 3
mov eax, esi
mov edx, dword [ebp - 0x18]
add edx, 0xfffffff0
lock xadd dword [edx + 0xc], eax
dec eax
test eax, eax
jg 0x428576
mov ecx, dword [edx]
push edx
mov eax, dword [ecx]
call dword [eax + 4]
mov byte [ebp - 4], 1
mov eax, esi
mov edx, dword [ebp - 0x20]
add edx, 0xfffffff0
lock xadd dword [edx + 0xc], eax
dec eax
test eax, eax
jg 0x428594
mov ecx, dword [edx]
push edx
mov eax, dword [ecx]
call dword [eax + 4]
mov edi, dword [ebp - 0x1c]
mov byte [ebp - 4], 0
add ebx, 0xfffffff0
mov eax, esi
lock xadd dword [ebx + 0xc], eax
dec eax
test eax, eax
jg 0x4285b2
mov ecx, dword [ebx]
push ebx
mov eax, dword [ecx]
call dword [eax + 4]
mov dword [ebp - 4], 0xffffffff
mov eax, dword [ebp + 8]
add eax, 0xfffffff0
lock xadd dword [eax + 0xc], esi
dec esi
test esi, esi
jg 0x4285d1
mov ecx, dword [eax]
push eax
mov edx, dword [ecx]
call dword [edx + 4]
mov eax, edi
mov ecx, dword [ebp - 0xc]
mov dword fs:[0], ecx
pop ecx
pop edi
pop esi
pop ebx
mov esp, ebp
pop ebp
ret