| File name: | zlib1__.dll |
| Full analysis: | https://app.any.run/tasks/7d8287ea-d57f-4d91-9f90-950989055a56 |
| Verdict: | Malicious activity |
| Threats: | A backdoor is a type of cybersecurity threat that allows attackers to secretly compromise a system and conduct malicious activities, such as stealing data and modifying files. Backdoors can be difficult to detect, as they often use legitimate system applications to evade defense mechanisms. Threat actors often utilize special malware, such as PlugX, to establish backdoors on target devices. |
| Analysis date: | December 17, 2024, 14:17:41 |
| OS: | Windows 10 Professional (build: 19045, 64 bit) |
| Tags: | |
| Indicators: | |
| MIME: | application/vnd.microsoft.portable-executable |
| File info: | PE32+ executable (DLL) (console) x86-64 (stripped to external PDB), for MS Windows, 12 sections |
| MD5: | D82D8AAA68F631B2781DCB5A4A63529B |
| SHA1: | 05FCE5514F033E1D0A83FC5CC8BA5C256AF70713 |
| SHA256: | 5D7448391CABFFADA07FB8136D9BD519E9D653875BD176DD49E771B5DBD0EAB2 |
| SSDEEP: | 1536:9TDbqcWxwgRYPQ/35nl6O5N6GlnSTzMlrVQopCmDimjmxBsRdM1uVPVRauWR+:NbqXLRB/Ga/YzoK4v6BsbM1P+ |
MALICIOUS
FLOXIF has been detected (YARA)
- WerFault.exe (PID: 6812)
SUSPICIOUS
Executes application which crashes
- rundll32.exe (PID: 6632)
The process creates files with name similar to system file names
- WerFault.exe (PID: 6812)
INFO
Reads the software policy settings
- WerFault.exe (PID: 6812)
The sample compiled with english language support
- rundll32.exe (PID: 6632)
Checks proxy server information
- WerFault.exe (PID: 6812)
Creates files or folders in the user directory
- WerFault.exe (PID: 6812)
Find more information about signature artifacts and mapping to MITRE ATT&CK™ MATRIX at the full report
TRiD
| .exe | | | Win64 Executable (generic) (87.2) |
|---|---|---|
| .exe | | | Generic Win/DOS Executable (6.3) |
| .exe | | | DOS Executable Generic (6.3) |
EXIF
EXE
| MachineType: | AMD AMD64 |
|---|---|
| TimeStamp: | 0000:00:00 00:00:00 |
| ImageFileCharacteristics: | Executable, No line numbers, No symbols, Large address aware, No debug, DLL |
| PEType: | PE32+ |
| LinkerVersion: | 2.32 |
| CodeSize: | 76800 |
| InitializedDataSize: | 109056 |
| UninitializedDataSize: | 2560 |
| EntryPoint: | 0x1330 |
| OSVersion: | 4 |
| ImageVersion: | - |
| SubsystemVersion: | 5.2 |
| Subsystem: | Windows command line |
| FileVersionNumber: | 1.2.11.0 |
| ProductVersionNumber: | 1.2.11.0 |
| FileFlagsMask: | 0x003f |
| FileFlags: | (none) |
| FileOS: | Win32 |
| ObjectFileType: | Dynamic link library |
| FileSubtype: | - |
| LanguageCode: | English (U.S.) |
| CharacterSet: | Windows, Latin1 |
| FileDescription: | zlib data compression library |
| FileVersion: | 1.2.11 |
| InternalName: | zlib1.dll |
| LegalCopyright: | (C) 1995-2017 Jean-loup Gailly & Mark Adler |
| OriginalFileName: | zlib1.dll |
| ProductName: | zlib |
| ProductVersion: | 1.2.11 |
| Comments: | For more information visit http://www.zlib.net/ |
Total processes
129
Monitored processes
2
Malicious processes
2
Suspicious processes
0
Behavior graph
Click at the process to see the details
Process information
PID | CMD | Path | Indicators | Parent process | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 6632 | "C:\WINDOWS\System32\rundll32.exe" C:\Users\admin\AppData\Local\Temp\zlib1__.dll, #1 | C:\Windows\System32\rundll32.exe | explorer.exe | ||||||||||||
User: admin Company: Microsoft Corporation Integrity Level: MEDIUM Description: Windows host process (Rundll32) Exit code: 3221225477 Version: 10.0.19041.1 (WinBuild.160101.0800) Modules
| |||||||||||||||
| 6812 | C:\WINDOWS\system32\WerFault.exe -u -p 6632 -s 356 | C:\Windows\System32\WerFault.exe | rundll32.exe | ||||||||||||
User: admin Company: Microsoft Corporation Integrity Level: MEDIUM Description: Windows Problem Reporting Exit code: 0 Version: 10.0.19041.1 (WinBuild.160101.0800) Modules
| |||||||||||||||
Total events
3 285
Read events
3 285
Write events
0
Delete events
0
Modification events
Executable files
0
Suspicious files
6
Text files
2
Unknown types
0
Dropped files
PID | Process | Filename | Type | |
|---|---|---|---|---|
| 6812 | WerFault.exe | C:\ProgramData\Microsoft\Windows\WER\ReportArchive\AppCrash_rundll32.exe_zli_c867be821652a5fe45b1c9b6d2871b8dc2ca7d_79898b83_b8bd3f19-f543-4ac3-85f4-11744b169e82\Report.wer | — | |
MD5:— | SHA256:— | |||
| 6812 | WerFault.exe | C:\ProgramData\Microsoft\Windows\WER\Temp\WER5B93.tmp.xml | xml | |
MD5:3CAE0FA3E28C5182BBC94888965AD29C | SHA256:C4F17A27C2DBD8F63CC19447D9F6843FBB5605E07BC1AD779BB1D662D659B2B8 | |||
| 6812 | WerFault.exe | C:\Users\admin\AppData\LocalLow\Microsoft\CryptnetUrlCache\Content\21253908F3CB05D51B1C2DA8B681A785 | binary | |
MD5:F6F53CD09A41E968C363419B279D3112 | SHA256:6D2BB01CC7A9BADE2113B219CAC1BDA86B2733196B7E1BD0C807CE1E396B1892 | |||
| 6812 | WerFault.exe | C:\ProgramData\Microsoft\Windows\WER\Temp\WER5B63.tmp.WERInternalMetadata.xml | xml | |
MD5:4377EEA3F20437ACD926873ED9755366 | SHA256:DB90350305D2945A405556DF577A3196B9E7F5CE849221743356F4F263093625 | |||
| 6812 | WerFault.exe | C:\ProgramData\Microsoft\Windows\WER\Temp\WER5AD5.tmp.dmp | binary | |
MD5:3C241D047C0DB05CC705483B3C8BDEC2 | SHA256:19252971B49C2A36AAB29DD9EBE50A0582E82018D77ACA38A5815606DAA1C3CA | |||
| 6812 | WerFault.exe | C:\Users\admin\AppData\LocalLow\Microsoft\CryptnetUrlCache\MetaData\37C951188967C8EB88D99893D9D191FE | binary | |
MD5:FB26941913C7B34DB65B6FB96CEE86C3 | SHA256:CE365BAC3513369C36946A37E03A251E72E8BCA38E399734F732985F72C04FAC | |||
| 6812 | WerFault.exe | C:\Users\admin\AppData\LocalLow\Microsoft\CryptnetUrlCache\Content\37C951188967C8EB88D99893D9D191FE | der | |
MD5:FA84E4BCC92AA5DB735AB50711040CDE | SHA256:6D7205E794FDE4219A62D9692ECDDF612663A5CF20399E79BE87B851FCA4CA33 | |||
| 6812 | WerFault.exe | C:\Users\admin\AppData\LocalLow\Microsoft\CryptnetUrlCache\MetaData\21253908F3CB05D51B1C2DA8B681A785 | binary | |
MD5:C191E3431816908A3E8D4CB8BBE231E5 | SHA256:ADB05DFB55FF53310A0CAEE380ABB03AC8D12C1D1F02ADCA5E5808701F5DDF74 | |||
| 6812 | WerFault.exe | C:\Users\admin\AppData\Local\CrashDumps\rundll32.exe.6632.dmp | binary | |
MD5:5466F19089CEACCE8D9DB2BB7B92DD48 | SHA256:4DB2E3829F5936BDC0D3DE148CD1577C6EF048041DC0C5B00A6F01C0B0C4AACC | |||
Download PCAP, analyze network streams, HTTP content and a lot more at the full report
HTTP(S) requests
11
TCP/UDP connections
34
DNS requests
18
Threats
0
HTTP requests
PID | Process | Method | HTTP Code | IP | URL | CN | Type | Size | Reputation |
|---|---|---|---|---|---|---|---|---|---|
1356 | svchost.exe | GET | 200 | 2.16.164.106:80 | http://crl.microsoft.com/pki/crl/products/MicRooCerAut2011_2011_03_22.crl | unknown | — | — | whitelisted |
4712 | MoUsoCoreWorker.exe | GET | 200 | 2.16.164.106:80 | http://crl.microsoft.com/pki/crl/products/MicRooCerAut2011_2011_03_22.crl | unknown | — | — | whitelisted |
1356 | svchost.exe | GET | 200 | 88.221.169.152:80 | http://www.microsoft.com/pkiops/crl/MicSecSerCA2011_2011-10-18.crl | unknown | — | — | whitelisted |
4712 | MoUsoCoreWorker.exe | GET | 200 | 88.221.169.152:80 | http://www.microsoft.com/pkiops/crl/MicSecSerCA2011_2011-10-18.crl | unknown | — | — | whitelisted |
1176 | svchost.exe | GET | 200 | 192.229.221.95:80 | http://ocsp.digicert.com/MFEwTzBNMEswSTAJBgUrDgMCGgUABBSAUQYBMq2awn1Rh6Doh%2FsBYgFV7gQUA95QNVbRTLtm8KPiGxvDl7I90VUCEAJ0LqoXyo4hxxe7H%2Fz9DKA%3D | unknown | — | — | whitelisted |
— | — | GET | 200 | 192.229.221.95:80 | http://ocsp.digicert.com/MFEwTzBNMEswSTAJBgUrDgMCGgUABBTrjrydRyt%2BApF3GSPypfHBxR5XtQQUs9tIpPmhxdiuNkHMEWNpYim8S8YCEAI5PUjXAkJafLQcAAsO18o%3D | unknown | — | — | whitelisted |
6432 | backgroundTaskHost.exe | GET | 200 | 192.229.221.95:80 | http://ocsp.digicert.com/MFEwTzBNMEswSTAJBgUrDgMCGgUABBQ50otx%2Fh0Ztl%2Bz8SiPI7wEWVxDlQQUTiJUIBiV5uNu5g%2F6%2BrkS7QYXjzkCEAUZZSZEml49Gjh0j13P68w%3D | unknown | — | — | whitelisted |
6812 | WerFault.exe | GET | 200 | 23.48.23.156:80 | http://crl.microsoft.com/pki/crl/products/MicRooCerAut2011_2011_03_22.crl | unknown | — | — | whitelisted |
6812 | WerFault.exe | GET | 200 | 184.30.21.171:80 | http://www.microsoft.com/pkiops/crl/MicSecSerCA2011_2011-10-18.crl | unknown | — | — | whitelisted |
1596 | SIHClient.exe | GET | 200 | 184.30.21.171:80 | http://www.microsoft.com/pkiops/crl/Microsoft%20ECC%20Product%20Root%20Certificate%20Authority%202018.crl | unknown | — | — | whitelisted |
Download PCAP, analyze network streams, HTTP content and a lot more at the full report
Connections
PID | Process | IP | Domain | ASN | CN | Reputation |
|---|---|---|---|---|---|---|
— | — | 20.73.194.208:443 | — | MICROSOFT-CORP-MSN-AS-BLOCK | NL | whitelisted |
— | — | 192.168.100.255:137 | — | — | — | whitelisted |
1356 | svchost.exe | 2.16.164.106:80 | crl.microsoft.com | Akamai International B.V. | NL | whitelisted |
4712 | MoUsoCoreWorker.exe | 2.16.164.106:80 | crl.microsoft.com | Akamai International B.V. | NL | whitelisted |
1356 | svchost.exe | 88.221.169.152:80 | www.microsoft.com | AKAMAI-AS | DE | whitelisted |
4712 | MoUsoCoreWorker.exe | 88.221.169.152:80 | www.microsoft.com | AKAMAI-AS | DE | whitelisted |
4 | System | 192.168.100.255:138 | — | — | — | whitelisted |
1176 | svchost.exe | 20.190.159.23:443 | login.live.com | MICROSOFT-CORP-MSN-AS-BLOCK | IE | whitelisted |
5064 | SearchApp.exe | 2.23.209.156:443 | www.bing.com | Akamai International B.V. | GB | whitelisted |
1176 | svchost.exe | 192.229.221.95:80 | ocsp.digicert.com | EDGECAST | US | whitelisted |
DNS requests
Domain | IP | Reputation |
|---|---|---|
crl.microsoft.com |
| whitelisted |
www.microsoft.com |
| whitelisted |
google.com |
| whitelisted |
login.live.com |
| whitelisted |
www.bing.com |
| whitelisted |
ocsp.digicert.com |
| whitelisted |
go.microsoft.com |
| whitelisted |
watson.events.data.microsoft.com |
| whitelisted |
settings-win.data.microsoft.com |
| whitelisted |
arc.msn.com |
| whitelisted |