cbcvebase.
CVE-2020-1599
published 2020-11-11

CVE-2020-1599: Windows Spoofing Vulnerability Windows Spoofing Vulnerability

medium5.5CVSS 3.1
AVLACLPRLUINSUCNIHAN
ITWVulnCheck KEVRansomware
Exploited in the wild
EPSS
19.12%
97.0th percentile
Windows Spoofing Vulnerability Windows Spoofing Vulnerability

Affected

39 ranges· showing 25
VendorProductVersion rangeFixed in
microsoftwindows_10_version_1507>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1607>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1803>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1809>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1903_for_32-bit_systems>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1903_for_arm64-based_systems>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1903_for_x64-based_systems>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1909>= 10.0.0 < publicationpublication
microsoftwindows_10_version_2004>= 10.0.0 < publicationpublication
microsoftwindows_10_version_20h2>= 10.0.0 < publicationpublication
microsoftwindows_7>= 6.1.0 < publicationpublication
microsoftwindows_7_service_pack_1>= 6.1.0 < publicationpublication
microsoftwindows_8.1>= 6.3.0 < publicationpublication
microsoftwindows_server_2008_r2_service_pack_1>= 6.0.0 < publicationpublication
microsoftwindows_server_2008_r2_service_pack_1>= 6.1.0 < publicationpublication
microsoftwindows_server_2008_service_pack_2>= 6.0.0 < publicationpublication
microsoftwindows_server_2012>= 6.2.0 < publicationpublication
microsoftwindows_server_2012_r2>= 6.3.0 < publicationpublication
microsoftwindows_server_2016>= 10.0.0 < publicationpublication
microsoftwindows_server_2019>= 10.0.0 < publicationpublication
microsoftwindows_server_version_2004>= 10.0.0 < publicationpublication
microsoftwindows_server_version_20h2>= 10.0.0 < publicationpublication
msrcwindows_10
msrcwindows_10_version_1607
msrcwindows_10_version_1803

Detection & IOCsextracted from sources · hover to see the quote

hashA6ED1667BB4BB9BAC35CE937FF08C7216D63EBB4
domainteamworks455[.]com
domainlkjhgfgsdshja[.]com
ip185[.]191[.]34[.]209
filenamedefenderr.bat
filenameload.bat
filename9092.dll
filenameadminpriv.exe
filenameappContast.dll
filenamereboot.dll
filenameauto.bat
filenameWScriptSleeper.vbs
registryHKCU\Software\Microsoft\Windows\CurrentVersion\Run
commandmshta.exe appContast.dll
commandregsvr32.exe 9092.dll
domainpornislife[.]online
  • Detect mshta.exe being invoked with a DLL file (e.g., appContast.dll or reboot.dll) as a parameter — this is the exploitation mechanism for CVE-2020-1599, where a Microsoft-signed PE file has a VBScript/JavaScript payload appended to its signature section and is executed via mshta.exe.
  • Alert on regsvr32.exe spawning from or being chained after mshta.exe, particularly loading DLLs from %appdata% — indicative of Zloader payload execution following CVE-2020-1599 abuse.
  • Monitor for msiexec.exe making outbound network connections — Zloader injects into msiexec.exe which then beacons to the C2.
  • Detect WScriptSleeper.vbs being written to the %temp% directory — a staging artifact specific to this Zloader campaign.
  • Flag auto.bat placed in the Startup folder that invokes mshta.exe with a DLL parameter — persistence mechanism for this campaign.
  • Detect modification of HKCU\Software\Microsoft\Windows\CurrentVersion\Run to execute regsvr32.exe with a DLL from a newly created %appdata% subfolder — Zloader run-key persistence.
  • Inspect PE files for appended data beyond the Authenticode signature boundary (modified file checksum and signature size fields) — the core technique exploited by CVE-2020-1599 to maintain a valid signature on a tampered file.
  • ·The campaign payload DLL (9092.dll) changes hash every few days via a server-side check.php script, making hash-based detection unreliable for this family.
  • ·zoom.dll referenced in the persistence chain was missing at time of analysis, indicating the campaign was still under active development and additional components may appear.

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
nvdv2.02.1LOWAV:L/AC:L/Au:N/C:N/I:P/A:N
cvelistv55.5MEDIUM
vulncheck5.5MEDIUM
vendor_msrc5.5MEDIUM
vendor_redhat3.3LOW
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