to compare with
вторник, 3 июля 2018 г.
пятница, 29 июня 2018 г.
interesting case of memory leak
after three weeks of work service osqueryd.exe consumed about 150 mb of memory. so I made full memory dump with process explorer and run !heap -l in windbg
298991 string in log ! lets write quick and ditry perl script to calculate sizes of leaked blocks:
298991 string in log ! lets write quick and ditry perl script to calculate sizes of leaked blocks:
my $state = 0; my($str, %dict, $size); while( $str = <> ) { chomp $str; last if ( $str eq '' ); if ( ! $state ) { $state = 1 if ( $str =~ /^-----/ ); next; } $str = substr($str, 72, 10); $str =~ s/^\s+//g; $str =~ s/\s+$//g; $size = hex($str); next if ( !$size ); $dict{$size} += 1; } # dump results my $iter; foreach $iter ( sort { $dict{$b} <=> $dict{$a} } keys %dict ) { printf("%X %d\n", $iter, $dict{$iter}); }results are encouraging:
среда, 17 января 2018 г.
wincheck rc8.60
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mirror
Changelog:
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Changelog:
- add some support of meltdown patched kernels. It seems that Microsoft backported from w10 InterruptObject to KPRCB on windows 8.1. so all offsets below this field were shifted downward and previous version of wincheck produced BSODs
- add dumping of SYSTEM_KERNEL_VA_SHADOW_INFORMATION
- add support of windows 10 build 17063
- add lots of new WNF IDs names from ADK version 10.1.16299
пятница, 24 ноября 2017 г.
wincheck rc8.59
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Changelog:
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Changelog:
- add support of numerous versions of windows 10 insider preview - up to ~17025
- add -dsip option to dump SIPs from crypt32.dll
- add -dac & -dsac options to dump activation contexts and system activation contexts. based on this code from @deroko
- add dumping of rpcrt4 security providers
- add dumping of ETW private loggers (-wmi option)
- add lots of WNF IDs names
- add dumping of registered with winnsi!NsiRpcRegisterChangeNotification notifications
четверг, 16 ноября 2017 г.
crypt32.dll SIPs
in cool paper "subverting windows trust" was described mechanism of subject interface package (SIP)
Lets see how we can extract and dump them
Unfortunately list of SIPs inside crypt32.dll don't have name in .pdb. One way is to find it with help of IDA Pro from function FindDll:
this address (I named it dll_list) contains head of linked list to SIPs structures like this:
Lets see how we can extract and dump them
Unfortunately list of SIPs inside crypt32.dll don't have name in .pdb. One way is to find it with help of IDA Pro from function FindDll:
push [ebp+nSize] ; nSize
push ebx ; lpDst
push [ebp+lpSrc] ; lpSrc
call ds:__imp__ExpandEnvironmentStringsW@12
test eax, eax
jz short loc_5CF28F50
push offset dll_cs call ds:__imp__EnterCriticalSection@4
mov edi, dll_list ; linked list of SIPs
test edi, edi
jz short loc_5CF28F89
next_item:
push 0FFFFFFFFh ; cchCount2
push dword ptr [edi+8] ; lpString2
push 0FFFFFFFFh ; cchCount1
push ebx ; lpString1
push 1 ; dwCmpFlags
push 409h ; Locale
call ds:__imp__CompareStringW@24
dec eax
sub eax, 1
jz short loc_5CF28F41
mov edi, [edi+4]
test edi, edi
jnz short next_itemthis address (I named it dll_list) contains head of linked list to SIPs structures like this:
struct sip_item
{
sip_item *next;
PVOID unk4; // ptr to crypto32_dll_list_item
const char *fname; // actually ends to end of sip_item
PVOID pfn; // if function was resolved, else NULL
};
struct crypto32_dll_list_item
{
PVOID unk;
crypto32_dll_list_item *next;
const wchar_t *dll_name; HANDLE base; // if dll was loaded - load base else NULL
DWORD unk10;
DWORD unk14;
sip_item *func_items_list;
PVOID unk20;
PVOID unk24;
PVOID unk28;
};вторник, 7 ноября 2017 г.
rpcrt4 security providers
Count of loaded providers stored in rpcrt4!LoadedProviders and list in rpcrt4!ProviderList
Structure of each provider can be partially recovered from function FindSecurityPackage:
It's interesting that the function of InitSecurityFunctionTable patches the contents of SECURITY_FUNCTION_TABLE. Sample of output from w8.1:
Structure of each provider can be partially recovered from function FindSecurityPackage:
struct _rpc_loaded_provider{ DWORD unk1; PVOID unk2; PSecurityFunctionTable table; PVOID unk3; PVOID unk4; }; // size of struct 0x14 for x86 and 0x28 for x64
It's interesting that the function of InitSecurityFunctionTable patches the contents of SECURITY_FUNCTION_TABLE. Sample of output from w8.1:
четверг, 2 ноября 2017 г.
how to find rpcrt4!GlobalRpcServer
I looked through sources of rpcview and found that they used some kind of brute-force in file RpcCore.c in function GetRpcServerAddressInProcess. It looks very strange and slow - they already has some code for pdb reading, so why not just ask address of ?GlobalRpcServer@@3PEAVRPC_SERVER@@EA ?
Anyway there is better way. Lets run my exref.pl in IDA Pro on rpcrt4.dll from windows 10 build 16278:
wow, it seems that this will be easy
Lets look at exported function I_RpcServerRegisterForwardFunction:
Anyway there is better way. Lets run my exref.pl in IDA Pro on rpcrt4.dll from windows 10 build 16278:
_I_RpcServerUseProtseq2W@20: 4EFACEB0 addr 4EFACEED
_RpcServerInqBindings@4: 4EFADA90 addr 4EFADAAC
_RpcServerRegisterIfEx@24: 4EFADCB0 addr 4EFADCCC
_RpcMgmtIsServerListening@4: 4EFAE470 addr 4EFAE48D
_RpcServerInterfaceGroupActivate@4: 4EFAE5B0 addr 4EFAE5C2
_RpcServerInterfaceGroupDeactivate@8: 4EFAE5E0 addr 4EFAE5F2
_I_RpcServerUseProtseqEp2W@24: 4EFB33E0 addr 4EFB33FF
_RpcServerUnregisterIf@12: 4EFB50B0 addr 4EFB50C5
_RpcServerRegisterIf3@32: 4EFB51F0 addr 4EFB5222
_RpcServerRegisterIf2@28: 4EFDFF40 addr 4EFDFF5C
_RpcServerInqBindingsEx@8: 4EFE0080 addr 4EFE0098
_RpcServerRegisterIf@12: 4EFE02E0 addr 4EFE02F5
_I_RpcServerRegisterForwardFunction@4: 4EFE03E0 addr 4EFE03F2
_RpcServerInterfaceGroupInqBindings@8: 4F0070D0 addr 4F0070E7
_RpcServerUseAllProtseqsEx@12: 4F007150 addr 4F00722Cwow, it seems that this will be easy
Lets look at exported function I_RpcServerRegisterForwardFunction:
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