MalwareBazaar Database

You are currently viewing the MalwareBazaar entry for SHA256 b7bf04a5d5d14c38358fb28f8e2453bf45926684769ad6a79a4bf110d8587af5. While MalwareBazaar tries to identify whether the sample provided is malicious or not, there is no guarantee that a sample in MalwareBazaar is malicious.

Database Entry


OskiStealer


Vendor detections: 11


Intelligence 11 IOCs 7 YARA 7 File information Comments
Download sample Add tag Delete this sample Report a False Positive

SHA256 hash: b7bf04a5d5d14c38358fb28f8e2453bf45926684769ad6a79a4bf110d8587af5
SHA3-384 hash: 80c6e2117dcd1ae25b3949668f581ab5c3d02d6a9fe960cc532962511e9bb042ff6c3464a91006d49f81f0ccc432293b
SHA1 hash: acad6550d0d9a43d791cd5aaf78237053ab2e9e2
MD5 hash: 3e0559f907c481442d53ac625c3d98b0
humanhash: tango-september-oscar-enemy
File name:os.exe
Download: download sample
Signature OskiStealer
Create hunting rule
File size:480'320 bytes
First seen:2022-07-21 13:42:29 UTC
Last seen:2022-07-22 03:11:15 UTC
File type:Executable exe
MIME type:application/x-dosexec
imphash f34d5f2d4577ed6d9ceec516c1f5a744 (48'649 x AgentTesla, 19'461 x Formbook, 12'202 x SnakeKeylogger)
ssdeep 12288:8eDlusrbBqKn3g2L8NRQL5k/pjlR94kNEcN:8eBumbBqKn3gNRjlj4q
Threatray 4'440 similar samples on MalwareBazaar
TLSH T160A4F13076708A4CCE03BFF234E226C6D9D86E5B1A34946125CF7765B6733BC26AD621
TrID 71.1% (.EXE) Generic CIL Executable (.NET, Mono, etc.) (73123/4/13)
10.2% (.EXE) Win64 Executable (generic) (10523/12/4)
6.3% (.DLL) Win32 Dynamic Link Library (generic) (6578/25/2)
4.3% (.EXE) Win32 Executable (generic) (4505/5/1)
2.0% (.EXE) Win16/32 Executable Delphi generic (2072/23)
File icon (PE):PE icon
dhash icon e09a676060678ee0 (14 x AsyncRAT, 5 x ValleyRAT, 4 x Formbook)
Reporter James_inthe_box
Tags:exe OskiStealer

Indicators Of Compromise (IOCs)

Below is a list of indicators of compromise (IOCs) associated with this malware samples.

IOCThreatFox Reference
http://raslack.axwebsite.com/6.jpg https://threatfox.abuse.ch/ioc/839027/
http://raslack.axwebsite.com/1.jpg https://threatfox.abuse.ch/ioc/839028/
http://raslack.axwebsite.com/2.jpg https://threatfox.abuse.ch/ioc/839029/
http://raslack.axwebsite.com/3.jpg https://threatfox.abuse.ch/ioc/839030/
http://raslack.axwebsite.com/4.jpg https://threatfox.abuse.ch/ioc/839031/
http://raslack.axwebsite.com/5.jpg https://threatfox.abuse.ch/ioc/839032/
http://raslack.axwebsite.com/7.jpg https://threatfox.abuse.ch/ioc/839033/

Intelligence

File Origin
# of uploads :
3
# of downloads :
304
Origin country :
n/a
Vendor Threat Intelligence
Malware family:
n/a
ID:
1
File name:
https://www59.zippyshare.com/d/8o8nZNCx/373251/os.exe
Verdict:
Malicious activity
Analysis date:
2022-07-21 05:18:47 UTC
Tags:
n/a
Link:
https://app.any.run/tasks/cb05898d-adcd-4a42-a3c2-5fd0e05420ba

Note:
ANY.RUN is an interactive sandbox that analyzes all user actions rather than an uploaded sample
Detection:
n/a
Link:
https://www.capesandbox.com/analysis/293192/
Detection(s):
SecuriteInfo.com.Trojan.Inject4.38227.20217.27378.UNOFFICIAL
Create hunting rule

Result
Verdict:
Malware
Maliciousness:

Behaviour
Searching for the window
Creating a file
Launching a service
DNS request
Сreating synchronization primitives
Launching a process
Creating a process with a hidden window
Creating a window
Creating a file in the system32 subdirectories
Creating a file in the %AppData% directory
Running batch commands
Enabling autorun with the standard Software\Microsoft\Windows\CurrentVersion\Run registry branch
Forced shutdown of a system process
Launching a tool to kill processes
Unauthorized injection to a system process
Enabling autorun by creating a file
Verdict:
Likely Malicious
Threat level:
  7.5/10
Confidence:
100%
Tags:
overlay packed
Link:
https://www.filescan.io/uploads/62d958250e298a94f3e86f98/reports/88eda101-82af-4522-9a25-a00aeaacd87b/overview
Result
Verdict:
MALICIOUS
Details
Windows PE Executable
Found a Windows Portable Executable (PE) binary. Depending on context, the presence of a binary is suspicious or malicious.
Malware family:
Oski Stealer
Create hunting rule
Verdict:
Malicious
Link:
https://analyze.intezer.com/analyses/b95da478-ca8c-43cf-87de-6d1d6ed5bfe7
Result
Threat name:
Oski Stealer, Vidar
Create hunting rule
Detection:
malicious
Classification:
troj.spyw.evad
Score:
100 / 100
Link:
https://www.joesandbox.com/analysis/1038646
Signature
.NET source code contains potential unpacker
.NET source code contains very large array initializations
Allocates memory in foreign processes
Antivirus detection for URL or domain
C2 URLs / IPs found in malware configuration
DLL side loading technique detected
Downloads files with wrong headers with respect to MIME Content-Type
Encrypted powershell cmdline option found
Found many strings related to Crypto-Wallets (likely being stolen)
Icon mismatch, binary includes an icon from a different legit application in order to fool users
Injects a PE file into a foreign processes
Machine Learning detection for dropped file
Machine Learning detection for sample
Malicious sample detected (through community Yara rule)
Posts data to a JPG file (protocol mismatch)
Snort IDS alert for network traffic
Tries to harvest and steal browser information (history, passwords, etc)
Tries to steal Crypto Currency Wallets
Writes to foreign memory regions
Yara detected Oski Stealer
Yara detected Vidar stealer
Behaviour
Behavior Graph:
Download SVG
behaviorgraph top1 signatures2 2 Behavior Graph ID: 671141 Sample: os.exe Startdate: 21/07/2022 Architecture: WINDOWS Score: 100 63 Snort IDS alert for network traffic 2->63 65 Malicious sample detected (through community Yara rule) 2->65 67 Antivirus detection for URL or domain 2->67 69 12 other signatures 2->69 8 os.exe 1 4 2->8         started        12 YES EXE.exe 2 2->12         started        14 YES EXE.exe 2->14         started        process3 file4 53 C:\Users\user\AppData\Roaming\YES EXE.exe, PE32 8->53 dropped 55 C:\Users\user\...\YES EXE.exe:Zone.Identifier, ASCII 8->55 dropped 57 C:\Users\user\AppData\Local\...\os.exe.log, ASCII 8->57 dropped 77 Encrypted powershell cmdline option found 8->77 79 Writes to foreign memory regions 8->79 81 Allocates memory in foreign processes 8->81 16 InstallUtil.exe 196 8->16         started        21 powershell.exe 15 8->21         started        23 InstallUtil.exe 8->23         started        83 Injects a PE file into a foreign processes 12->83 25 InstallUtil.exe 12->25         started        27 powershell.exe 12->27         started        29 InstallUtil.exe 14->29         started        31 powershell.exe 14->31         started        signatures5 process6 dnsIp7 59 raslack.axwebsite.com 144.76.115.36, 49792, 49799, 49812 HETZNER-ASDE Germany 16->59 45 C:\ProgramData\sqlite3.dll, PE32 16->45 dropped 47 C:\ProgramData\vcruntime140.dll, PE32 16->47 dropped 49 C:\ProgramData\softokn3.dll, PE32 16->49 dropped 51 4 other files (none is malicious) 16->51 dropped 71 Tries to harvest and steal browser information (history, passwords, etc) 16->71 73 DLL side loading technique detected 16->73 75 Tries to steal Crypto Currency Wallets 16->75 33 cmd.exe 16->33         started        35 conhost.exe 21->35         started        37 conhost.exe 27->37         started        61 192.168.2.1 unknown unknown 29->61 39 conhost.exe 31->39         started        file8 signatures9 process10 process11 41 conhost.exe 33->41         started        43 taskkill.exe 33->43         started       
Detection:
n/a
Link:
https://mwdb.cert.pl/sample/b7bf04a5d5d14c38358fb28f8e2453bf45926684769ad6a79a4bf110d8587af5/
Threat name:
ByteCode-MSIL.Trojan.FormBook
Create hunting rule
Status:
Malicious
First seen:
2022-07-21 13:41:46 UTC
File Type:
PE (.Net Exe)
Extracted files:
11
AV detection:
21 of 26 (80.77%)
Threat level:
  5/5
Detection(s):
Suspicious file
Link:
https://check.spamhaus.org/check/?searchterm=w67qjjov2fgdqnmpwkhy4jctx5czezueo2nnnj42jpyrbwcypl2q._file
Verdict:
malicious
Similar samples:
0c6058dd764f4921fcb201f1c7fb7a9f24ae2c4ade920ff36fe29886cd6a8f7e
OskiStealer
191db013c67081442ef5e75edd00c2572f6ec9d7f629ddac9bba8942722c061d
OskiStealer
6107e3ec5898ce2f80b04ee16b3a41107a0733339cded01cf8c5ade5fc105472
OskiStealer
6849e65e9ac20880fa99583b202ae710e0a3885cd72692a0c1b4d72aae109adf
OskiStealer
89ec309c384717284199d66d01669738ce37d9fb445a8f7f2259dfd6ca888f5d
OskiStealer
ae672a54491d01385af7932cc9524889f6314dd4b4b8b9a846dfa1ffedaa8c61
OskiStealer
+ 4'430 additional samples on MalwareBazaar
Result
Malware family:
oski
Create hunting rule
Score:
  10/10
Tags:
family:oski infostealer persistence spyware suricata
Link:
https://tria.ge/reports/220721-qz8gdafgg2/
Behaviour
Checks processor information in registry
Kills process with taskkill
Suspicious behavior: EnumeratesProcesses
Suspicious use of AdjustPrivilegeToken
Suspicious use of WriteProcessMemory
Enumerates physical storage devices
Suspicious use of SetThreadContext
Accesses cryptocurrency files/wallets, possible credential harvesting
Adds Run key to start application
Checks computer location settings
Loads dropped DLL
Downloads MZ/PE file
Oski
suricata: ET MALWARE Suspicious Zipped Filename in Outbound POST Request (Passwords.txt)
suricata: ET MALWARE Suspicious Zipped Filename in Outbound POST Request (Passwords.txt) M2
suricata: ET MALWARE Vidar/Arkei/Megumin/Oski Stealer Data Exfil
suricata: ET MALWARE Vidar/Arkei/Megumin/Oski Stealer HTTP POST Pattern
Malware Config
C2 Extraction:
raslack.axwebsite.com
Unpacked files
SH256 hash:
e46c303490f0f77e5ff861d754dd591599a31d73241ae2c231c93c2f5eef8e96
MD5 hash:
ad61a338d9d18acf21cfb8f440a90ba7
SHA1 hash:
e3d4664ac747b30ce94ee34cfde6d96cedc23ce5
Link:
https://www.unpac.me/results/0c8ad170-3d09-4863-8e00-ae0bdf7fd38e/
SH256 hash:
b7bf04a5d5d14c38358fb28f8e2453bf45926684769ad6a79a4bf110d8587af5
MD5 hash:
3e0559f907c481442d53ac625c3d98b0
SHA1 hash:
acad6550d0d9a43d791cd5aaf78237053ab2e9e2
Link:
https://www.unpac.me/results/0c8ad170-3d09-4863-8e00-ae0bdf7fd38e/
Please note that we are no longer able to provide a coverage score for Virus Total.
Threat name:
Legit
Score:
0.00
Link:
https://yomi.yoroi.company/submissions/b7bf04a5d5d14c38358fb28f8e2453bf45926684769ad6a79a4bf110d8587af5

YARA Signatures

MalwareBazaar uses YARA rules from several public and non-public repositories, such as YARAhub and Malpedia. Those are being matched against malware samples uploaded to MalwareBazaar as well as against any suspicious process dumps they may create. Please note that only results from TLP:CLEAR rules are being displayed.

Rule name:cobalt_strike_tmp01925d3f
Create hunting rule
Author:The DFIR Report
Description:files - file ~tmp01925d3f.exe
Reference:https://thedfirreport.com
Rule name:INDICATOR_KB_CERT_1f3216f428f850be2c66caa056f6d821
Create hunting rule
Author:ditekSHen
Description:Detects executables signed with stolen, revoked or invalid certificates
Rule name:MALWARE_Win_Vidar
Create hunting rule
Author:ditekSHen
Description:Detects Vidar / ArkeiStealer
Rule name:pe_imphash
Create hunting rule
Rule name:Skystars_Malware_Imphash
Create hunting rule
Author:Skystars LightDefender
Description:imphash
Rule name:Vidar
Create hunting rule
Author:kevoreilly
Description:Vidar Payload
Rule name:win_oski_auto
Create hunting rule
Author:Felix Bilstein - yara-signator at cocacoding dot com
Description:Detects win.oski.

File information

The table below shows additional information about this malware sample such as delivery method and external references.

  
Delivery method
Other
Cape
Cape
https://www.capesandbox.com/analysis/293192/

Comments