MalwareBazaar Database
You are currently viewing the MalwareBazaar entry for SHA256 436651743894169dc9cd4c7ef01734420a5ce2d6dcaf57825197e0c756feeee9. 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
Maldoc score: 14
| SHA256 hash: | 436651743894169dc9cd4c7ef01734420a5ce2d6dcaf57825197e0c756feeee9 |
|---|---|
| SHA3-384 hash: | 11dd586711cab1e8d9fea751730400b4e1d1e21a4b4b175feffe28db331cb87f49f1333e8dfa4525b2eab198fb74d678 |
| SHA1 hash: | c3c6a82ee16f87ebacdd8be47018be38b6c98a27 |
| MD5 hash: | 2d827df1ee25674aac2060c37efa2fe7 |
| humanhash: | coffee-oregon-shade-foxtrot |
| File name: | fileattached.xlsm |
| Download: | download sample |
| Signature | OskiStealer |
| File size: | 13'243 bytes |
| First seen: | 2021-08-05 18:26:21 UTC |
| Last seen: | Never |
| File type: |  xlsm |
| MIME type: | application/vnd.openxmlformats-officedocument.spreadsheetml.sheet |
| ssdeep | 192:c0JgCGIUxP4NydRxeRIaFUlbVvevUqzRdgNi/ciE+c8++4Yj1v9:ZuI04NUgRFUlM9zrSpT8b99 |
| TLSH | T159528D0EE753702DC377A43AC95815F8E51E6061A82A758A3844BB7D68432D753CFBF4 |
| Reporter |  abuse_ch |
| Tags: | OskiStealer xlsm |
Indicators Of Compromise (IOCs)
Below is a list of indicators of compromise (IOCs) associated with this malware samples.
| IOC | ThreatFox Reference |
|---|---|
| http://notedemo.axfree.com/6.jpg | https://threatfox.abuse.ch/ioc/165845/ |
| http://notedemo.axfree.com/1.jpg | https://threatfox.abuse.ch/ioc/165846/ |
| http://notedemo.axfree.com/2.jpg | https://threatfox.abuse.ch/ioc/165847/ |
| http://notedemo.axfree.com/3.jpg | https://threatfox.abuse.ch/ioc/165848/ |
| http://notedemo.axfree.com/4.jpg | https://threatfox.abuse.ch/ioc/165849/ |
| http://notedemo.axfree.com/5.jpg | https://threatfox.abuse.ch/ioc/165850/ |
| http://notedemo.axfree.com/7.jpg | https://threatfox.abuse.ch/ioc/165851/ |
Office OLE Information
This malware samples appears to be an Office document. The following table provides more information about this document using oletools and oledump.
OLE id
| Maldoc score: 14 |
OLE vba
MalwareBazaar was able to extract and deobfuscate VBA script(s) the following information from OLE objects embedded in this file using olevba:
| Type | Keyword | Description |
|---|---|---|
| IOC | zJAMC.exe | Executable file name |
| Suspicious | powershell | May run PowerShell commands |
| Suspicious | nEw-oBjecT | May create an OLE object using PowerShell |
| Suspicious | Net.WebcLIENt | May download files from the Internet using PowerShell |
| Suspicious | EXEC | May run an executable file or a system |
| Suspicious | Hex Strings | Hex-encoded strings were detected, may be used to obfuscate strings (option --decode to see all) |
| Suspicious | Base64 Strings | Base64-encoded strings were detected, may be used to obfuscate strings (option --decode to see all) |
| Suspicious | XLM macrosheet | XLM macrosheet found. It could contain malicious code |
Intelligence
File Origin
# of uploads :
1
# of downloads :
176
Origin country :
n/a
Vendor Threat Intelligence
Malware family:
n/a
ID:
1
File name:
fileattached.xlsm
Verdict:
Malicious activity
Analysis date:
2021-08-05 18:26:52 UTC
Tags:
trojan stealer vidar loader
Note:
ANY.RUN is an interactive sandbox that analyzes all user actions rather than an uploaded sample
Verdict:
Malicious
File type:
application/vnd.ms-excel.sheet.macroEnabled.12
Has a screenshot:
False
Contains macros:
False
Detection:
n/a
Result
Verdict:
Malware
Maliciousness:
Behaviour
Creating a window
Creating a process with a hidden window
Launching a process
Sending a UDP request
DNS request
Connection attempt
Sending an HTTP GET request
Sending a custom TCP request
Creating a file in the %temp% directory
Creating a process from a recently created file
Running batch commands by exploiting the app vulnerability
Launching a process by exploiting the app vulnerability
Result
Verdict:
Malicious
File Type:
OOXML Excel File with Excel4Macro
Payload URLs
URL
File name
http://iurl.vip/bij0o',$env
intlsheet1.xml
Result
Verdict:
MALICIOUS
Link:
Details
Macro Execution Coercion
Detected a document that appears to social engineer the user into activating embedded logic.
Macro Contains Suspicious String
Detected a macro with a suspicious string. Suspicious strings include privileged function calls, obfuscations, odd registry keys, etc...
Autostarting Excel Macro Sheet
Excel contains Macrosheet logic that will trigger automatically upon document open.
Document With Minimal Content
Document contains less than 1 kilobyte of semantic information.
Result
Threat name:
Oski
Detection:
malicious
Classification:
troj.expl.evad
Score:
100 / 100
Signature
.NET source code contains potential unpacker
Document exploit detected (process start blacklist hit)
Found malware configuration
Machine Learning detection for dropped file
Multi AV Scanner detection for submitted file
Obfuscated command line found
Office document tries to convince victim to disable security protection (e.g. to enable ActiveX or Macros)
Powershell drops PE file
Sigma detected: Microsoft Office Product Spawning Windows Shell
Sigma detected: Suspicious Script Execution From Temp Folder
Yara detected Oski Stealer
Behaviour
Behavior Graph:
Threat name:
Script.Downloader.Powdow
Status:
Malicious
First seen:
2021-08-05 18:27:07 UTC
AV detection:
12 of 46 (26.09%)
Threat level:
3/5
Detection(s):
Suspicious file
Result
Malware family:
oski
Score:
10/10
Tags:
family:oski infostealer macro spyware suricata xlm
Behaviour
Checks processor information in registry
Enumerates system info in registry
Kills process with taskkill
Modifies Internet Explorer settings
Suspicious behavior: AddClipboardFormatListener
Suspicious behavior: EnumeratesProcesses
Suspicious use of AdjustPrivilegeToken
Suspicious use of SetWindowsHookEx
Suspicious use of WriteProcessMemory
An obfuscated cmd.exe command-line is typically used to evade detection.
Suspicious use of SetThreadContext
Accesses cryptocurrency files/wallets, possible credential harvesting
Loads dropped DLL
Uses the VBS compiler for execution
Downloads MZ/PE file
Executes dropped EXE
Blocklisted process makes network request
Oski
Process spawned unexpected child process
suricata: ET MALWARE Suspicious Zipped Filename in Outbound POST Request (Passwords.txt)
suricata: ET MALWARE Vidar/Arkei/Megumin/Oski Stealer Data Exfil
Malware Config
C2 Extraction:
notedemo.axfree.com
Dropper Extraction:
http://iurl.vip/bij0o
Verdict:
Malicious
Please note that we are no longer able to provide a coverage score for Virus Total.
Threat name:
Malicious File
Score:
1.00
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: | MALWARE_Win_Vidar |
|---|---|
| Author: | ditekSHen |
| Description: | Detects Vidar / ArkeiStealer |
| Rule name: | Microsoft_XLSX_with_Macrosheet |
|---|
| Rule name: | Microsoft_XLSX_with_Macrosheet |
|---|
| Rule name: | Vidar |
|---|---|
| Author: | kevoreilly |
| Description: | Vidar Payload |
| Rule name: | win_oski_auto |
|---|---|
| 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.
Comments
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