Analysis

  • max time kernel
    207s
  • max time network
    187s
  • platform
    windows7_x64
  • resource
    win7-20220812-en
  • resource tags

    arch:x64arch:x86image:win7-20220812-enlocale:en-usos:windows7-x64system
  • submitted
    29-12-2022 14:57

General

  • Target

    AA_v3.exe

  • Size

    778KB

  • MD5

    121e1634bf18768802427f0a13f039a9

  • SHA1

    8868654ba10fb4c9a7bd882d1f947f4fd51e988e

  • SHA256

    5fc600351bade74c2791fc526bca6bb606355cc65e5253f7f791254db58ee7fa

  • SHA512

    393df326af3109fe701b579b73f42f7a9b155bb4df6ea7049ad3ae9fdd03446576b887a99eb7a0d59949a7a63367e223253448b6f1a0ebeaf358fa2873dcc200

  • SSDEEP

    12288:hSX+EvrCA3FNIs34Zk1L1ZSNlm3Spsal6lbRtMuStGKcsCSqcl90Va1ugp:2FNN4Zk1LTclm3e1kbRtyGKcpHcl517p

Score
10/10

Malware Config

Signatures

  • FlawedAmmyy RAT

    Remote-access trojan based on leaked code for the Ammyy remote admin software.

  • Blocklisted process makes network request 1 IoCs
  • Checks computer location settings 2 TTPs 1 IoCs

    Looks up country code configured in the registry, likely geofence.

  • Loads dropped DLL 4 IoCs
  • Drops file in System32 directory 11 IoCs
  • Enumerates system info in registry 2 TTPs 3 IoCs
  • Modifies data under HKEY_USERS 64 IoCs
  • Modifies system certificate store 2 TTPs 6 IoCs
  • Suspicious behavior: EnumeratesProcesses 9 IoCs
  • Suspicious use of AdjustPrivilegeToken 5 IoCs
  • Suspicious use of FindShellTrayWindow 36 IoCs
  • Suspicious use of SendNotifyMessage 33 IoCs
  • Suspicious use of WriteProcessMemory 64 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\AA_v3.exe
    "C:\Users\Admin\AppData\Local\Temp\AA_v3.exe"
    1⤵
      PID:1996
    • C:\Users\Admin\AppData\Local\Temp\AA_v3.exe
      "C:\Users\Admin\AppData\Local\Temp\AA_v3.exe" -service -lunch
      1⤵
      • Suspicious use of WriteProcessMemory
      PID:1988
      • C:\Users\Admin\AppData\Local\Temp\AA_v3.exe
        "C:\Users\Admin\AppData\Local\Temp\AA_v3.exe"
        2⤵
        • Checks computer location settings
        • Drops file in System32 directory
        • Modifies data under HKEY_USERS
        • Modifies system certificate store
        • Suspicious use of FindShellTrayWindow
        • Suspicious use of SendNotifyMessage
        • Suspicious use of WriteProcessMemory
        PID:1740
        • C:\Windows\system32\rundll32.exe
          rundll32.exe "C:\ProgramData\AMMYY\aa_nts.dll",run
          3⤵
          • Blocklisted process makes network request
          • Loads dropped DLL
          • Suspicious behavior: EnumeratesProcesses
          • Suspicious use of AdjustPrivilegeToken
          PID:824
    • C:\Program Files\Google\Chrome\Application\chrome.exe
      "C:\Program Files\Google\Chrome\Application\chrome.exe"
      1⤵
      • Enumerates system info in registry
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of FindShellTrayWindow
      • Suspicious use of SendNotifyMessage
      • Suspicious use of WriteProcessMemory
      PID:360
      • C:\Program Files\Google\Chrome\Application\chrome.exe
        "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=crashpad-handler "--user-data-dir=C:\Users\Admin\AppData\Local\Google\Chrome\User Data" /prefetch:7 --monitor-self-annotation=ptype=crashpad-handler "--database=C:\Users\Admin\AppData\Local\Google\Chrome\User Data\Crashpad" "--metrics-dir=C:\Users\Admin\AppData\Local\Google\Chrome\User Data" --url=https://clients2.google.com/cr/report --annotation=channel= --annotation=plat=Win64 --annotation=prod=Chrome --annotation=ver=89.0.4389.114 --initial-client-data=0xc0,0xc4,0xc8,0x94,0xcc,0x7fefab14f50,0x7fefab14f60,0x7fefab14f70
        2⤵
          PID:1872
        • C:\Program Files\Google\Chrome\Application\chrome.exe
          "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=gpu-process --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --gpu-preferences=SAAAAAAAAADgAAAwAAAAAAAAAAAAAAAAAABgAAAAAAAoAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAB4AAAAAAAAAHgAAAAAAAAAKAAAAAQAAAAgAAAAAAAAACgAAAAAAAAAMAAAAAAAAAA4AAAAAAAAABAAAAAAAAAAAAAAAAUAAAAQAAAAAAAAAAAAAAAGAAAAEAAAAAAAAAABAAAABQAAABAAAAAAAAAAAQAAAAYAAAAIAAAAAAAAAAgAAAAAAAAA --mojo-platform-channel-handle=1040 /prefetch:2
          2⤵
            PID:576
          • C:\Program Files\Google\Chrome\Application\chrome.exe
            "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=network.mojom.NetworkService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=network --mojo-platform-channel-handle=1468 /prefetch:8
            2⤵
            • Suspicious behavior: EnumeratesProcesses
            PID:908
          • C:\Program Files\Google\Chrome\Application\chrome.exe
            "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=storage.mojom.StorageService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=1828 /prefetch:8
            2⤵
              PID:672
            • C:\Program Files\Google\Chrome\Application\chrome.exe
              "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=renderer --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --device-scale-factor=1 --num-raster-threads=1 --renderer-client-id=6 --no-v8-untrusted-code-mitigations --mojo-platform-channel-handle=2032 /prefetch:1
              2⤵
                PID:1032
              • C:\Program Files\Google\Chrome\Application\chrome.exe
                "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=renderer --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --device-scale-factor=1 --num-raster-threads=1 --renderer-client-id=5 --no-v8-untrusted-code-mitigations --mojo-platform-channel-handle=2052 /prefetch:1
                2⤵
                  PID:1376
                • C:\Program Files\Google\Chrome\Application\chrome.exe
                  "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=2600 /prefetch:8
                  2⤵
                    PID:1068
                  • C:\Program Files\Google\Chrome\Application\chrome.exe
                    "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=gpu-process --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --gpu-preferences=SAAAAAAAAADgAAAwAAAAAAAAAAAAAAAAAABgAAAAAAAoAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAB4AAAAAAAAAHgAAAAAAAAAKAAAAAQAAAAgAAAAAAAAACgAAAAAAAAAMAAAAAAAAAA4AAAAAAAAABAAAAAAAAAAAAAAAAUAAAAQAAAAAAAAAAAAAAAGAAAAEAAAAAAAAAABAAAABQAAABAAAAAAAAAAAQAAAAYAAAAIAAAAAAAAAAgAAAAAAAAA --use-gl=swiftshader-webgl --mojo-platform-channel-handle=3300 /prefetch:2
                    2⤵
                      PID:2100
                    • C:\Program Files\Google\Chrome\Application\chrome.exe
                      "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=renderer --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --disable-gpu-compositing --lang=en-US --device-scale-factor=1 --num-raster-threads=1 --renderer-client-id=9 --no-v8-untrusted-code-mitigations --mojo-platform-channel-handle=1304 /prefetch:1
                      2⤵
                        PID:2144
                      • C:\Program Files\Google\Chrome\Application\chrome.exe
                        "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=3668 /prefetch:8
                        2⤵
                          PID:2220
                        • C:\Program Files\Google\Chrome\Application\chrome.exe
                          "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=3724 /prefetch:8
                          2⤵
                            PID:2228
                          • C:\Program Files\Google\Chrome\Application\chrome.exe
                            "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=3888 /prefetch:8
                            2⤵
                              PID:2236
                            • C:\Program Files\Google\Chrome\Application\chrome.exe
                              "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=3992 /prefetch:8
                              2⤵
                                PID:2300
                              • C:\Program Files\Google\Chrome\Application\chrome.exe
                                "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=1776 /prefetch:8
                                2⤵
                                  PID:2396
                                • C:\Program Files\Google\Chrome\Application\chrome.exe
                                  "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=1744 /prefetch:8
                                  2⤵
                                    PID:2404
                                  • C:\Program Files\Google\Chrome\Application\chrome.exe
                                    "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=984 /prefetch:8
                                    2⤵
                                      PID:2412
                                    • C:\Program Files\Google\Chrome\Application\chrome.exe
                                      "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=3984 /prefetch:8
                                      2⤵
                                        PID:2504
                                      • C:\Program Files\Google\Chrome\Application\chrome.exe
                                        "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=3804 /prefetch:8
                                        2⤵
                                          PID:2512
                                        • C:\Program Files\Google\Chrome\Application\chrome.exe
                                          "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=3848 /prefetch:8
                                          2⤵
                                            PID:2520
                                          • C:\Program Files\Google\Chrome\Application\chrome.exe
                                            "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=4320 /prefetch:8
                                            2⤵
                                              PID:2540
                                            • C:\Program Files\Google\Chrome\Application\chrome.exe
                                              "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=4260 /prefetch:8
                                              2⤵
                                                PID:2528
                                              • C:\Program Files\Google\Chrome\Application\chrome.exe
                                                "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=4460 /prefetch:8
                                                2⤵
                                                  PID:2548
                                                • C:\Program Files\Google\Chrome\Application\chrome.exe
                                                  "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=4128 /prefetch:8
                                                  2⤵
                                                    PID:2724
                                                  • C:\Program Files\Google\Chrome\Application\chrome.exe
                                                    "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=4312 /prefetch:8
                                                    2⤵
                                                      PID:2732
                                                    • C:\Program Files\Google\Chrome\Application\chrome.exe
                                                      "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=renderer --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --disable-gpu-compositing --lang=en-US --device-scale-factor=1 --num-raster-threads=1 --renderer-client-id=25 --no-v8-untrusted-code-mitigations --mojo-platform-channel-handle=2564 /prefetch:1
                                                      2⤵
                                                        PID:2796
                                                      • C:\Program Files\Google\Chrome\Application\chrome.exe
                                                        "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=renderer --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --disable-gpu-compositing --lang=en-US --device-scale-factor=1 --num-raster-threads=1 --renderer-client-id=26 --no-v8-untrusted-code-mitigations --mojo-platform-channel-handle=2152 /prefetch:1
                                                        2⤵
                                                          PID:2864
                                                        • C:\Program Files\Google\Chrome\Application\chrome.exe
                                                          "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=renderer --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --disable-gpu-compositing --lang=en-US --device-scale-factor=1 --num-raster-threads=1 --renderer-client-id=27 --no-v8-untrusted-code-mitigations --mojo-platform-channel-handle=3752 /prefetch:1
                                                          2⤵
                                                            PID:2948
                                                          • C:\Program Files\Google\Chrome\Application\chrome.exe
                                                            "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=renderer --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --disable-gpu-compositing --lang=en-US --device-scale-factor=1 --num-raster-threads=1 --renderer-client-id=28 --no-v8-untrusted-code-mitigations --mojo-platform-channel-handle=4232 /prefetch:1
                                                            2⤵
                                                              PID:2956
                                                            • C:\Program Files\Google\Chrome\Application\chrome.exe
                                                              "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=audio.mojom.AudioService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=audio --mojo-platform-channel-handle=2484 /prefetch:8
                                                              2⤵
                                                                PID:2056
                                                              • C:\Program Files\Google\Chrome\Application\chrome.exe
                                                                "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=2184 /prefetch:8
                                                                2⤵
                                                                  PID:1068
                                                                • C:\Program Files\Google\Chrome\Application\chrome.exe
                                                                  "C:\Program Files\Google\Chrome\Application\chrome.exe" --type=utility --utility-sub-type=data_decoder.mojom.DataDecoderService --field-trial-handle=1012,7857237402941026852,5735977801127589591,131072 --lang=en-US --service-sandbox-type=utility --mojo-platform-channel-handle=4476 /prefetch:8
                                                                  2⤵
                                                                    PID:2304
                                                                • C:\Windows\system32\AUDIODG.EXE
                                                                  C:\Windows\system32\AUDIODG.EXE 0x560
                                                                  1⤵
                                                                  • Suspicious use of AdjustPrivilegeToken
                                                                  PID:2076

                                                                Network

                                                                MITRE ATT&CK Enterprise v6

                                                                Replay Monitor

                                                                Loading Replay Monitor...

                                                                Downloads

                                                                • C:\ProgramData\AMMYY\aa_nts.dll

                                                                  Filesize

                                                                  902KB

                                                                  MD5

                                                                  480a66902e6e7cdafaa6711e8697ff8c

                                                                  SHA1

                                                                  6ac730962e7c1dba9e2ecc5733a506544f3c8d11

                                                                  SHA256

                                                                  7eaaaa6010bbcd6bb8c9ad08d4b0966c7aedc9b2ac24758f170012ac36e508b5

                                                                  SHA512

                                                                  7d010cd47b7d1adf66f9c97afc6c3805997aa5c7cc6ff13eddee81f24cf2b95a3fe375ec5b3d6185c0bc8840b4ad91ae143c73a39af26391cc182ab6a1793ba5

                                                                • C:\ProgramData\AMMYY\aa_nts.msg

                                                                  Filesize

                                                                  45B

                                                                  MD5

                                                                  4caaf991b110b739ce514cbe5a4adf1e

                                                                  SHA1

                                                                  0db6e969ddd5b0deb5fa706d9dedd6e2ff40fd8b

                                                                  SHA256

                                                                  e243f29f7360abe17cb9c14185e2e366d03ade7e52bb87477205f1046faef035

                                                                  SHA512

                                                                  752206aa8a37f8e178a77d7190fe0800567c4946a96734544c2163ce0798198deb4d2eed89afc9c42eef94511dd2651e53b586df02d79b20fb81c782f5e8293a

                                                                • C:\ProgramData\AMMYY\settings3.bin

                                                                  Filesize

                                                                  282B

                                                                  MD5

                                                                  ac7221c691ef0a93dbbb5bee6efcb7ec

                                                                  SHA1

                                                                  54f197fef16badefb4bf0d7339f6bd1099e505da

                                                                  SHA256

                                                                  b6b033b71d3f7f92986e32a61b3244b9856e82a9c3d233696a0dfa29a517106f

                                                                  SHA512

                                                                  226299ab1b7b388473163f4fecc41d536755586b4c275475128c5e5946554cd9ca69df223469130d85516f2ac2330a2cb35dec2879355ea0186b63d8429dcd6b

                                                                • \ProgramData\AMMYY\aa_nts.dll

                                                                  Filesize

                                                                  902KB

                                                                  MD5

                                                                  480a66902e6e7cdafaa6711e8697ff8c

                                                                  SHA1

                                                                  6ac730962e7c1dba9e2ecc5733a506544f3c8d11

                                                                  SHA256

                                                                  7eaaaa6010bbcd6bb8c9ad08d4b0966c7aedc9b2ac24758f170012ac36e508b5

                                                                  SHA512

                                                                  7d010cd47b7d1adf66f9c97afc6c3805997aa5c7cc6ff13eddee81f24cf2b95a3fe375ec5b3d6185c0bc8840b4ad91ae143c73a39af26391cc182ab6a1793ba5

                                                                • \ProgramData\AMMYY\aa_nts.dll

                                                                  Filesize

                                                                  902KB

                                                                  MD5

                                                                  480a66902e6e7cdafaa6711e8697ff8c

                                                                  SHA1

                                                                  6ac730962e7c1dba9e2ecc5733a506544f3c8d11

                                                                  SHA256

                                                                  7eaaaa6010bbcd6bb8c9ad08d4b0966c7aedc9b2ac24758f170012ac36e508b5

                                                                  SHA512

                                                                  7d010cd47b7d1adf66f9c97afc6c3805997aa5c7cc6ff13eddee81f24cf2b95a3fe375ec5b3d6185c0bc8840b4ad91ae143c73a39af26391cc182ab6a1793ba5

                                                                • \ProgramData\AMMYY\aa_nts.dll

                                                                  Filesize

                                                                  902KB

                                                                  MD5

                                                                  480a66902e6e7cdafaa6711e8697ff8c

                                                                  SHA1

                                                                  6ac730962e7c1dba9e2ecc5733a506544f3c8d11

                                                                  SHA256

                                                                  7eaaaa6010bbcd6bb8c9ad08d4b0966c7aedc9b2ac24758f170012ac36e508b5

                                                                  SHA512

                                                                  7d010cd47b7d1adf66f9c97afc6c3805997aa5c7cc6ff13eddee81f24cf2b95a3fe375ec5b3d6185c0bc8840b4ad91ae143c73a39af26391cc182ab6a1793ba5

                                                                • \ProgramData\AMMYY\aa_nts.dll

                                                                  Filesize

                                                                  902KB

                                                                  MD5

                                                                  480a66902e6e7cdafaa6711e8697ff8c

                                                                  SHA1

                                                                  6ac730962e7c1dba9e2ecc5733a506544f3c8d11

                                                                  SHA256

                                                                  7eaaaa6010bbcd6bb8c9ad08d4b0966c7aedc9b2ac24758f170012ac36e508b5

                                                                  SHA512

                                                                  7d010cd47b7d1adf66f9c97afc6c3805997aa5c7cc6ff13eddee81f24cf2b95a3fe375ec5b3d6185c0bc8840b4ad91ae143c73a39af26391cc182ab6a1793ba5

                                                                • memory/824-59-0x0000000000000000-mapping.dmp

                                                                • memory/1740-56-0x0000000000000000-mapping.dmp

                                                                • memory/1996-54-0x0000000075281000-0x0000000075283000-memory.dmp

                                                                  Filesize

                                                                  8KB