iOS app crashed in thread wihtout app actions

My iOS application crashed. In crash log I've found such info:

Exception Type:  EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Triggered by Thread:  9

Thread 9 Crashed:
0   libsystem_kernel.dylib          0x39189c70 __workq_kernreturn + 8
1   libsystem_pthread.dylib         0x391eec1f _pthread_wqthread + 307
2   libsystem_pthread.dylib         0x391eead8 start_wqthread + 4

I have no idea how to interpret this. There are some additional actions happening in other thread but they looks ok. Any idea why thread which does nothing crashed?

Full crash report:

Incident Identifier: 10D06EC1-B25F-47C3-99B8-6940748ACB87
CrashReporter Key:   5b7280661b8ec1e78028ed23448f54ab51a78b2c
Hardware Model:      iPad4,5
Process:             MyApp [4949]
Path:                /var/mobile/Applications/584B97BE-1555-4B03-A00D-9A563AA71E48/MyApp.app/MyApp
Identifier:          com.me.myapp
Version:             2.0.0.1 (2.0.0.1)
Code Type:           ARM (Native)
Parent Process:      launchd [1]

Date/Time:           2014-08-07 10:58:24.111 +0200
OS Version:          iOS 7.1.2 (11D257)
Report Version:      104

Exception Type:  EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Triggered by Thread:  9

Thread 0:
0   libsystem_kernel.dylib          0x39176a50 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x39176849 mach_msg + 37
2   CoreFoundation                  0x2dfc55e5 __CFRunLoopServiceMachPort + 153
3   CoreFoundation                  0x2dfc3d4b __CFRunLoopRun + 859
4   CoreFoundation                  0x2df2e725 CFRunLoopRunSpecific + 521
5   CoreFoundation                  0x2df2e507 CFRunLoopRunInMode + 103
6   GraphicsServices                0x32e676cf GSEventRunModal + 135
7   UIKit                           0x3088f86d UIApplicationMain + 1133
8   Myapp                           0x00186623 main (main.m:20)
9   libdyld.dylib                   0x390d2ab5 start + 1

Thread 1:
0   libsystem_kernel.dylib          0x39176804 kevent64 + 24
1   libdispatch.dylib               0x390c5051 _dispatch_mgr_invoke + 229
2   libdispatch.dylib               0x390bf2df _dispatch_mgr_thread + 35

Thread 2 name:  com.apple.NSURLConnectionLoader
Thread 2:
0   libsystem_kernel.dylib          0x39176a50 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x39176849 mach_msg + 37
2   CoreFoundation                  0x2dfc55e5 __CFRunLoopServiceMachPort + 153
3   CoreFoundation                  0x2dfc3d05 __CFRunLoopRun + 789
4   CoreFoundation                  0x2df2e725 CFRunLoopRunSpecific + 521
5   CoreFoundation                  0x2df2e507 CFRunLoopRunInMode + 103
6   Foundation                      0x2e96f23d +[NSURLConnection(Loader) _resourceLoadLoop:] + 317
7   Foundation                      0x2e9e4a0b __NSThread__main__ + 1059
8   libsystem_pthread.dylib         0x391f0957 _pthread_body + 139
9   libsystem_pthread.dylib         0x391f08c7 _pthread_start + 99
10  libsystem_pthread.dylib         0x391eeae4 thread_start + 4

Thread 3 name:  com.apple.CFSocket.private
Thread 3:
0   libsystem_kernel.dylib          0x39189434 __select + 20
1   CoreFoundation                  0x2dfc94df __CFSocketManager + 483
2   libsystem_pthread.dylib         0x391f0957 _pthread_body + 139
3   libsystem_pthread.dylib         0x391f08c7 _pthread_start + 99
4   libsystem_pthread.dylib         0x391eeae4 thread_start + 4

Thread 4 name:  WebThread
Thread 4:
0   libsystem_kernel.dylib          0x39176a50 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x39176849 mach_msg + 37
2   CoreFoundation                  0x2dfc55e5 __CFRunLoopServiceMachPort + 153
3   CoreFoundation                  0x2dfc3d05 __CFRunLoopRun + 789
4   CoreFoundation                  0x2df2e725 CFRunLoopRunSpecific + 521
5   CoreFoundation                  0x2df2e507 CFRunLoopRunInMode + 103
6   WebCore                         0x364ccc71 RunWebThread(void*) + 417
7   libsystem_pthread.dylib         0x391f0957 _pthread_body + 139
8   libsystem_pthread.dylib         0x391f08c7 _pthread_start + 99
9   libsystem_pthread.dylib         0x391eeae4 thread_start + 4

Thread 5 name:  JavaScriptCore::BlockFree
Thread 5:
0   libsystem_kernel.dylib          0x39188f2c __psynch_cvwait + 24
1   libsystem_pthread.dylib         0x391eff63 _pthread_cond_wait + 519
2   libsystem_pthread.dylib         0x391f0d9d pthread_cond_wait + 37
3   JavaScriptCore                  0x2ef5d309 JSC::BlockAllocator::blockFreeingThreadMain() + 205
4   JavaScriptCore                  0x2ef5a971 WTF::wtfThreadEntryPoint(void*) + 13
5   libsystem_pthread.dylib         0x391f0957 _pthread_body + 139
6   libsystem_pthread.dylib         0x391f08c7 _pthread_start + 99
7   libsystem_pthread.dylib         0x391eeae4 thread_start + 4

Thread 6 name:  JavaScriptCore::Marking
Thread 6:
0   libsystem_kernel.dylib          0x39188f2c __psynch_cvwait + 24
1   libsystem_pthread.dylib         0x391eff63 _pthread_cond_wait + 519
2   libsystem_pthread.dylib         0x391f0d9d pthread_cond_wait + 37
3   JavaScriptCore                  0x2f0fbcb3 JSC::GCThread::waitForNextPhase() + 75
4   JavaScriptCore                  0x2f0fbd0d JSC::GCThread::gcThreadMain() + 49
5   JavaScriptCore                  0x2ef5a971 WTF::wtfThreadEntryPoint(void*) + 13
6   libsystem_pthread.dylib         0x391f0957 _pthread_body + 139
7   libsystem_pthread.dylib         0x391f08c7 _pthread_start + 99
8   libsystem_pthread.dylib         0x391eeae4 thread_start + 4

Thread 7:
0   libsystem_kernel.dylib          0x39176a50 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x39176849 mach_msg + 37
2   CoreFoundation                  0x2dfc55e5 __CFRunLoopServiceMachPort + 153
3   CoreFoundation                  0x2dfc3d05 __CFRunLoopRun + 789
4   CoreFoundation                  0x2df2e725 CFRunLoopRunSpecific + 521
5   CoreFoundation                  0x2df72347 CFRunLoopRun + 95
6   CoreMotion                      0x2e5ed4fd ___lldb_unnamed_function1426$$CoreMotion + 725
7   libsystem_pthread.dylib         0x391f0957 _pthread_body + 139
8   libsystem_pthread.dylib         0x391f08c7 _pthread_start + 99
9   libsystem_pthread.dylib         0x391eeae4 thread_start + 4

Thread 8:
0   libsystem_kernel.dylib          0x39188744 __lseek + 8
1   Foundation                      0x2e9aa02f -[NSConcreteFileHandle readDataOfLength:] + 119
2   MyApp                           0x001549b1 -[MyClass myMethod:] (MyClass.m:425)
3   MyApp                           0x001540d9 -[MyClass myMethod:] (MyClass.m:425)
4   MyApp                           0x004b58d9 -[MyClass myMethod:] (MyClass.m:425)
5   MyApp                           0x004b6bff -[MyClass myMethod:] (MyClass.m:425)
6   MyApp                           0x004b88e1 -[MyClass myMethod:] (MyClass.m:425)
7   MyApp                           0x004b0203 -[MyClass myMethod:] (MyClass.m:425)
8   CoreFoundation                  0x2dffe410 __invoking___ + 64
9   CoreFoundation                  0x2df48963 -[NSInvocation invoke] + 283
10  Foundation                      0x2e9d1d05 -[NSInvocationOperation main] + 109
11  Foundation                      0x2e92f871 -[__NSOperationInternal _start:] + 769
12  Foundation                      0x2e9d3741 __NSOQSchedule_f + 57
13  libdispatch.dylib               0x390c2cb9 _dispatch_queue_drain + 485
14  libdispatch.dylib               0x390bfc6b _dispatch_queue_invoke + 39
15  libdispatch.dylib               0x390c35ef _dispatch_root_queue_drain + 75
16  libdispatch.dylib               0x390c38d9 _dispatch_worker_thread2 + 53
17  libsystem_pthread.dylib         0x391eec15 _pthread_wqthread + 297
18  libsystem_pthread.dylib         0x391eead8 start_wqthread + 4

Thread 9 Crashed:
0   libsystem_kernel.dylib          0x39189c70 __workq_kernreturn + 8
1   libsystem_pthread.dylib         0x391eec1f _pthread_wqthread + 307
2   libsystem_pthread.dylib         0x391eead8 start_wqthread + 4

Thread 10:
0   libsystem_c.dylib               0x3911ff65 usleep$NOCANCEL + 1
1   libsystem_c.dylib               0x39139ffd abort + 81
2   libsystem_malloc.dylib          0x391b772d szone_error + 313
3   libsystem_malloc.dylib          0x391b79ef free_tiny_botch + 63
4   CoreFoundation                  0x2e012bb4 __CFBasicHashRehash + 2884
5   CoreFoundation                  0x2e01362c __CFBasicHashAddValue + 96
6   CoreFoundation                  0x2df2d850 CFBasicHashAddValue + 3320
7   CoreData                        0x2dd6d861 _PFFastMOCObjectWillChange + 217
8   CoreData                        0x2dd6d66f _PF_ManagedObject_WillChangeValueForKeyIndex + 211
9   CoreData                        0x2dd6d4ff _sharedIMPL_setvfk_core + 107
10  MyApp                           0x0019dcaf -[MyClass myMethod:] (MyClass.m:425)
11  MyApp                           0x0019ec49 -[MyClass myMethod:] (MyClass.m:425)
12  CoreFoundation                  0x2dffe410 __invoking___ + 64
13  CoreFoundation                  0x2df48963 -[NSInvocation invoke] + 283
14  Foundation                      0x2e9d1d05 -[NSInvocationOperation main] + 109
15  Foundation                      0x2e92f871 -[__NSOperationInternal _start:] + 769
16  Foundation                      0x2e9d3741 __NSOQSchedule_f + 57
17  libdispatch.dylib               0x390c2cb9 _dispatch_queue_drain + 485
18  libdispatch.dylib               0x390bfc6b _dispatch_queue_invoke + 39
19  libdispatch.dylib               0x390c35ef _dispatch_root_queue_drain + 75
20  libdispatch.dylib               0x390c38d9 _dispatch_worker_thread2 + 53
21  libsystem_pthread.dylib         0x391eec15 _pthread_wqthread + 297
22  libsystem_pthread.dylib         0x391eead8 start_wqthread + 4

Thread 9 crashed with ARM Thread State (32-bit):
    r0: 0x00000004    r1: 0x00000000      r2: 0x00000000      r3: 0x00000000
    r4: 0x276ea000    r5: 0x00060001      r6: 0x00008983      r7: 0x276e9fe0
    r8: 0x00000000    r9: 0xfffffffb     r10: 0x00000000     r11: 0x00000000
    ip: 0x00000170    sp: 0x276e9fc8      lr: 0x391eec23      pc: 0x39189c70
  cpsr: 0x40000010