Analysis
-
max time kernel
93s -
max time network
110s -
platform
windows10_x64 -
resource
win10v20210410 -
submitted
07-05-2021 11:00
Static task
static1
Behavioral task
behavioral1
Sample
Ybhfk.exe
Resource
win7v20210408
Behavioral task
behavioral2
Sample
Ybhfk.exe
Resource
win10v20210410
General
-
Target
Ybhfk.exe
-
Size
685KB
-
MD5
4087a6277a5288c9dfddee6b28895c0f
-
SHA1
21b5e3b09c99c6da44219e53dbbe02e3c155c53a
-
SHA256
afdbf26cb55fb5d7acb13eee328ced4ffd4fd1d42a72dc95fb1053b264ec45ee
-
SHA512
a9b0ce9bdb3fb683fadf5947efad71c66d0de9e2f5f680c78e98ac48ab6c47967f213c5bff880798f90f236612817e09b3519493d3fece6f66497c37469a56c8
Malware Config
Extracted
oski
209.141.40.19
Signatures
-
Oski
Oski is an infostealer targeting browser data, crypto wallets.
-
Downloads MZ/PE file
-
Loads dropped DLL 3 IoCs
Processes:
Ybhfk.exepid process 4072 Ybhfk.exe 4072 Ybhfk.exe 4072 Ybhfk.exe -
Reads user/profile data of web browsers 2 TTPs
Infostealers often target stored browser data, which can include saved credentials etc.
-
Accesses cryptocurrency files/wallets, possible credential harvesting 2 TTPs
-
Checks installed software on the system 1 TTPs
Looks up Uninstall key entries in the registry to enumerate software on the system.
-
Suspicious use of SetThreadContext 1 IoCs
Processes:
Ybhfk.exedescription pid process target process PID 2208 set thread context of 4072 2208 Ybhfk.exe Ybhfk.exe -
Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.
-
Checks processor information in registry 2 TTPs 1 IoCs
Processor information is often read in order to detect sandboxing environments.
Processes:
Ybhfk.exedescription ioc process Key value queried \REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0\ProcessorNameString Ybhfk.exe -
Kills process with taskkill 1 IoCs
Processes:
taskkill.exepid process 740 taskkill.exe -
Suspicious behavior: EnumeratesProcesses 2 IoCs
Processes:
Ybhfk.exepid process 2208 Ybhfk.exe 2208 Ybhfk.exe -
Suspicious use of AdjustPrivilegeToken 2 IoCs
Processes:
Ybhfk.exetaskkill.exedescription pid process Token: SeDebugPrivilege 2208 Ybhfk.exe Token: SeDebugPrivilege 740 taskkill.exe -
Suspicious use of WriteProcessMemory 15 IoCs
Processes:
Ybhfk.exeYbhfk.execmd.exedescription pid process target process PID 2208 wrote to memory of 4072 2208 Ybhfk.exe Ybhfk.exe PID 2208 wrote to memory of 4072 2208 Ybhfk.exe Ybhfk.exe PID 2208 wrote to memory of 4072 2208 Ybhfk.exe Ybhfk.exe PID 2208 wrote to memory of 4072 2208 Ybhfk.exe Ybhfk.exe PID 2208 wrote to memory of 4072 2208 Ybhfk.exe Ybhfk.exe PID 2208 wrote to memory of 4072 2208 Ybhfk.exe Ybhfk.exe PID 2208 wrote to memory of 4072 2208 Ybhfk.exe Ybhfk.exe PID 2208 wrote to memory of 4072 2208 Ybhfk.exe Ybhfk.exe PID 2208 wrote to memory of 4072 2208 Ybhfk.exe Ybhfk.exe PID 4072 wrote to memory of 1524 4072 Ybhfk.exe cmd.exe PID 4072 wrote to memory of 1524 4072 Ybhfk.exe cmd.exe PID 4072 wrote to memory of 1524 4072 Ybhfk.exe cmd.exe PID 1524 wrote to memory of 740 1524 cmd.exe taskkill.exe PID 1524 wrote to memory of 740 1524 cmd.exe taskkill.exe PID 1524 wrote to memory of 740 1524 cmd.exe taskkill.exe
Processes
-
C:\Users\Admin\AppData\Local\Temp\Ybhfk.exe"C:\Users\Admin\AppData\Local\Temp\Ybhfk.exe"1⤵
- Suspicious use of SetThreadContext
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
-
C:\Users\Admin\AppData\Local\Temp\Ybhfk.exeC:\Users\Admin\AppData\Local\Temp\Ybhfk.exe2⤵
- Loads dropped DLL
- Checks processor information in registry
- Suspicious use of WriteProcessMemory
-
C:\Windows\SysWOW64\cmd.exe"C:\Windows\System32\cmd.exe" /c taskkill /pid 4072 & erase C:\Users\Admin\AppData\Local\Temp\Ybhfk.exe & RD /S /Q C:\\ProgramData\\291986200442781\\* & exit3⤵
- Suspicious use of WriteProcessMemory
-
C:\Windows\SysWOW64\taskkill.exetaskkill /pid 40724⤵
- Kills process with taskkill
- Suspicious use of AdjustPrivilegeToken
Network
MITRE ATT&CK Matrix ATT&CK v6
Replay Monitor
Loading Replay Monitor...
Downloads
-
\ProgramData\mozglue.dllMD5
8f73c08a9660691143661bf7332c3c27
SHA137fa65dd737c50fda710fdbde89e51374d0c204a
SHA2563fe6b1c54b8cf28f571e0c5d6636b4069a8ab00b4f11dd842cfec00691d0c9cd
SHA5120042ecf9b3571bb5eba2de893e8b2371df18f7c5a589f52ee66e4bfbaa15a5b8b7cc6a155792aaa8988528c27196896d5e82e1751c998bacea0d92395f66ad89
-
\ProgramData\nss3.dllMD5
bfac4e3c5908856ba17d41edcd455a51
SHA18eec7e888767aa9e4cca8ff246eb2aacb9170428
SHA256e2935b5b28550d47dc971f456d6961f20d1633b4892998750140e0eaa9ae9d78
SHA5122565bab776c4d732ffb1f9b415992a4c65b81bcd644a9a1df1333a269e322925fc1df4f76913463296efd7c88ef194c3056de2f1ca1357d7b5fe5ff0da877a66
-
\ProgramData\sqlite3.dllMD5
e477a96c8f2b18d6b5c27bde49c990bf
SHA1e980c9bf41330d1e5bd04556db4646a0210f7409
SHA25616574f51785b0e2fc29c2c61477eb47bb39f714829999511dc8952b43ab17660
SHA512335a86268e7c0e568b1c30981ec644e6cd332e66f96d2551b58a82515316693c1859d87b4f4b7310cf1ac386cee671580fdd999c3bcb23acf2c2282c01c8798c
-
memory/740-130-0x0000000000000000-mapping.dmp
-
memory/1524-129-0x0000000000000000-mapping.dmp
-
memory/2208-119-0x00000000058A0000-0x0000000005D9E000-memory.dmpFilesize
5.0MB
-
memory/2208-121-0x00000000075A0000-0x00000000075A1000-memory.dmpFilesize
4KB
-
memory/2208-122-0x0000000007710000-0x000000000772A000-memory.dmpFilesize
104KB
-
memory/2208-120-0x00000000074A0000-0x0000000007518000-memory.dmpFilesize
480KB
-
memory/2208-114-0x0000000000FA0000-0x0000000000FA1000-memory.dmpFilesize
4KB
-
memory/2208-118-0x0000000005880000-0x0000000005881000-memory.dmpFilesize
4KB
-
memory/2208-117-0x0000000005960000-0x0000000005961000-memory.dmpFilesize
4KB
-
memory/2208-116-0x0000000005DA0000-0x0000000005DA1000-memory.dmpFilesize
4KB
-
memory/4072-123-0x0000000000400000-0x0000000000438000-memory.dmpFilesize
224KB
-
memory/4072-124-0x000000000040717B-mapping.dmp
-
memory/4072-125-0x0000000000400000-0x0000000000438000-memory.dmpFilesize
224KB