IM-Worm.Win32.Bropia.aa malware suffers from an insecure permissions vulnerability.
695f9acb229dede25734a9ad77cdd57bDiscovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/ea6dfec6c3900ab422875119972d9c62.txt
Contact: [email protected]
Media: twitter.com/malvuln
Threat: IM-Worm.Win32.Bropia.aa
Vulnerability: Insecure Permissions
Description: The malware creates an hidden insecure dir named "tmpdata" under c:\ drive and grants change (C) permissions to the authenticated user group. Standard users can rename the executables dropped by the malware to disable it or replace it with their own executable. Then wait for a privileged user to logon to the infected machine to potentially escalate privileges.
Type: PE32
MD5: ea6dfec6c3900ab422875119972d9c62
Vuln ID: MVID-2021-0181
Dropped files: ImSexy.exe
Disclosure: 04/21/2021
Exploit/PoC:
C:\>cacls \tmpdata
C:\tmpdata BUILTIN\Administrators:(OI)(CI)(ID)F
NT AUTHORITY\SYSTEM:(OI)(CI)(ID)F
BUILTIN\Users:(OI)(CI)(ID)R
NT AUTHORITY\Authenticated Users:(ID)C
NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(ID)C
C:\>attrib -s -h \tmpdata
C:\>dir \tmpdata
Volume in drive C has no label.
Directory of C:\tmpdata
04/16/2021 09:10 AM 86,528 ImSexy.exe
1 File(s) 86,528 bytes
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