Check system files like the stickykey binary for modifications – not by comparing MD5 hashes from whitelist databases like the NSRL, but by comparing the expected content for a certain file name with the actual content of the file.Attackers modify their local “default.rdp” file and add “enablecredSSPsupport:i:0:1” in order to disable this behaviour.ĪPT detection therefore means the following:
Osk exe not is system32 folder password#
Windows 7+ users won’t stumble over it as they have Network Level Authentication (NLA) enabled by default, which prompts the user for username and password before fully establishing a Terminal Services connection. Another method sets the Windows command line as debugger for the stickykeys binary.Īs I already said, an Antivirus engine won’t detect this backdoor as the content of the file is a valid Windows executable with an intact signature. What they did was to copy a valid “cmd.exe” over the “sethc.exe” in the System32 folder in order to establish a backdoor that waits for the user pressing five times shift consecutively on a RDP logon screen and pops up a Windows command line running as LOCAL_SYSTEM. The “Sticky Keys” Backdoorĭuring our investigations we found that the attackers used a simple backdoor that allowed them to avoid AV detection and use tools that were already available on the target systems. What I recognized was that Metadata is the key to successful APT detection. Instead of looking at a file only by its content we collect numerous attributes and evaluate a score based on certain rules that indicate conspicuous features or anomalies. Only recently I recognized and named the methods that we apply since we introduced the scoring system in our scanner product. I’ll show you why APT detection is difficult – for the big players and spirited newcomers like us. But don’t worry, this blog post is just as little a sales pitch as it is an attempt to create a new product class. Copyright (c) 2020-2021 Strontic.People often ask me, why we changed the name of our scanner from “IOC” to “APT” scanner and if we did that only for marketing reasons. Default: “osk.exe” | String | osk.exe, sethc.exe, utilman.exe, magnify.exe, narrator.exe, DisplaySwitch.exe, atbroker.exe|ĭescription = “Abnormal osk.exe (On Screen Keyboard) - typical strings not found in file” | parent_list | Comma separated list of system binaries to which you want to attach each #. Upon successful execution, powershell will modify the registry and swap osk.exe with cmd.exe. * On-Screen Keyboard: C:\Windows\System32\osk.exe Each time osk.exe is run, cmd.exe will be run as well. Command : wmic.exe process call create "C:\Windows\system32\reg.exe add \"HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\osk.exe\" /v \"Debugger\" /t REG_SZ /d \"cmd.exe\" /f"ĭescription : Add cmd.exe as a debugger for the osk.exe process. TargetObject\|endswith : ' \SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Compatibility Assistant\Store\C:\Program Files\Windows Media Player\osk.exe' ' \SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\osk.exe\Debugger'
Registry_event_stickykey_like_backdoor.yml Image : ' C:\Program Files\Windows Media Player\osk.exe' Proc_creation_win_stickykey_like_backdoor.yml
Proc_creation_win_install_reg_debugger_backdoor.yml TargetFilename : ' C:\Program Files\Windows Media Player\osk.exe' While osk.exe is not inherently malicious, its legitimate functionality can be abused for malicious purposes. The following table contains possible examples of osk.exe being misused. Legal Copyright: Microsoft Corporation.Product Name: Microsoft Windows Operating System.Subject: CN=Microsoft Windows, O=Microsoft Corporation, L=Redmond, S=Washington, C=US.Issuer: CN=Microsoft Windows Production PCA 2011, O=Microsoft Corporation, L=Redmond, S=Washington, C=US.
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