MacOS – A lot of thesterious executable files inside /Users/Shared

disk-spacefindermacosvirus

Recently I've noticed that a lot of mysterious .tar.gz and executable files have spawned inside my Shared folder, and by a lot I mean 466 total.

/Users/Shared $ ls | wc -l
     466

I'm the only user on my Macbook Pro and out of the 466, I only recognized 6 of them being folders with an installed application name (CleanMyMac, Renewed Vision Media, etc) so those are not the problem. As for the rest, they look horrific:

    ls -l /Users/Shared
total 824456
drwxrwxr-x  5 root             wheel      160 Feb 12 14:38 Adobe
drwxrwxrwx  2 root             wheel       64 Aug 10  2018 AdobeInstalledCodecs
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb 12 10:02 App_01D422FE-C147-4010-9A44-D4358E33D212-1210-0000006734D5E80A
-rw-r--r--  1 jonathanfilbert  wheel   331578 Dec 17 10:32 App_01D422FE-C147-4010-9A44-D4358E33D212-1210-0000006734D5E80A.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb  6 15:28 App_02966A96-E2BC-48F1-A082-387BFD2559A6-1246-0000005E71CF0D2B
-rw-r--r--  1 jonathanfilbert  wheel  4660684 Jan 31 20:29 App_02966A96-E2BC-48F1-A082-387BFD2559A6-1246-0000005E71CF0D2B.tar.gz
drwxr-xr-x  3 jonathanfilbert  wheel       96 Dec  2 00:44 App_041C25CA-E276-4BBD-87FF-1AAF42FB62CF-1199-0000004DE163A3E6
-rw-r--r--  1 jonathanfilbert  wheel   331578 Dec  2 00:44 App_041C25CA-E276-4BBD-87FF-1AAF42FB62CF-1199-0000004DE163A3E6.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb  6 15:29 App_05BDF17A-375B-45DA-B054-D77F0BBA7061-1166-000000502FEEE31D
-rw-r--r--  1 jonathanfilbert  wheel  4660684 Dec 28 16:51 App_05BDF17A-375B-45DA-B054-D77F0BBA7061-1166-000000502FEEE31D.tar.gz
drwxr-xr-x  3 jonathanfilbert  wheel       96 Nov 26 13:54 App_070BFBA2-26D0-448F-9123-DADD3A2ECB49-1218-0000007FCF9E349B
-rw-r--r--  1 jonathanfilbert  wheel   331578 Nov 26 13:54 App_070BFBA2-26D0-448F-9123-DADD3A2ECB49-1218-0000007FCF9E349B.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb  6 15:28 App_0977FD4D-5953-4F70-BE63-FD750A3BF6DC-1231-0000005027783E91
-rw-r--r--  1 jonathanfilbert  wheel  4660684 Jan 11 12:44 App_0977FD4D-5953-4F70-BE63-FD750A3BF6DC-1231-0000005027783E91.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb  6 15:28 App_0A03682C-6DB4-4908-B386-A6BB644D3C74-1276-0000005B2AD5C511
-rw-r--r--  1 jonathanfilbert  wheel  4660684 Jan 17 11:10 App_0A03682C-6DB4-4908-B386-A6BB644D3C74-1276-0000005B2AD5C511.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb  6 15:28 App_0A8D9DBD-BAA7-444B-9E85-87972AF665EF-1216-0000005A3907D09A
-rw-r--r--  1 jonathanfilbert  wheel  4660684 Dec 23 15:53 App_0A8D9DBD-BAA7-444B-9E85-87972AF665EF-1216-0000005A3907D09A.tar.gz
drwxr-xr-x  3 jonathanfilbert  wheel       96 Dec  9 19:22 App_0ABFFC9E-731F-46BD-B117-17A76FBCA084-1236-0000004ED1B99385
-rw-r--r--  1 jonathanfilbert  wheel   331578 Dec  9 19:22 App_0ABFFC9E-731F-46BD-B117-17A76FBCA084-1236-0000004ED1B99385.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Mar 23 16:59 App_0C6FC480-EF97-4009-BF39-96F58799E7ED-1192-0000005E9FC8FC9F
-rw-r--r--  1 jonathanfilbert  wheel   331578 Dec 12 21:02 App_0C6FC480-EF97-4009-BF39-96F58799E7ED-1192-0000005E9FC8FC9F.tar.gz
drwxr-xr-x  3 jonathanfilbert  wheel       96 Dec 15 00:01 App_0DAD0990-45B0-4F11-A37A-DC9F8784C3C9-1185-000000610AEAD23D
-rw-r--r--  1 jonathanfilbert  wheel   331578 Dec 15 00:01 App_0DAD0990-45B0-4F11-A37A-DC9F8784C3C9-1185-000000610AEAD23D.tar.gz
drwxr-xr-x  3 jonathanfilbert  wheel       96 Nov 30 21:13 App_0F3DAB99-B214-4DBF-BBE4-A51C779F6987-1153-0000006B23FCBCB3
-rw-r--r--  1 jonathanfilbert  wheel   331578 Nov 30 21:13 App_0F3DAB99-B214-4DBF-BBE4-A51C779F6987-1153-0000006B23FCBCB3.tar.gz
drwxr-xr-x  3 jonathanfilbert  wheel       96 Dec  5 08:53 App_126A36AB-A0C5-4D4C-A23A-113EA6E7C970-1806-0000009535B1B6CB
-rw-r--r--  1 jonathanfilbert  wheel   331578 Dec  5 08:53 App_126A36AB-A0C5-4D4C-A23A-113EA6E7C970-1806-0000009535B1B6CB.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb 21 15:40 App_12E3E8A1-9788-4ABF-915A-F199A0C6143C-1221-000000541C12C17A
-rw-r--r--  1 jonathanfilbert  wheel   331578 Dec 16 14:36 App_12E3E8A1-9788-4ABF-915A-F199A0C6143C-1221-000000541C12C17A.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb  6 15:28 App_12EBEA64-5051-4122-89DF-9FB8DADAA41B-1275-00000063D967AF8B
-rw-r--r--  1 jonathanfilbert  wheel  4660684 Jan 11 23:07 App_12EBEA64-5051-4122-89DF-9FB8DADAA41B-1275-00000063D967AF8B.tar.gz
drwxr-xr-x  3 jonathanfilbert  wheel       96 Nov 19 15:51 App_149EDAB5-6A58-40F6-9FC8-B3E4F3279538-1218-0000006CC5FF38F4
-rw-r--r--  1 jonathanfilbert  wheel   331578 Nov 19 15:51 App_149EDAB5-6A58-40F6-9FC8-B3E4F3279538-1218-0000006CC5FF38F4.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb  6 15:28 App_16277D4A-ACA9-4730-8929-892500D29B19-1132-000000503FDB731F
-rw-r--r--  1 jonathanfilbert  wheel  4660684 Dec 31 14:57 App_16277D4A-ACA9-4730-8929-892500D29B19-1132-000000503FDB731F.tar.gz
drwxr-xr-x  3 jonathanfilbert  wheel       96 Nov  8 20:18 App_16A18583-FD97-4644-BF06-137B0FFD35E1-1204-0000006A2372C7CA
-rw-r--r--  1 jonathanfilbert  wheel   331578 Nov  8 20:18 App_16A18583-FD97-4644-BF06-137B0FFD35E1-1204-0000006A2372C7CA.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb  6 15:28 App_175B9F9E-2372-4165-AA2B-F0123E12ABEB-1895-00000095CD045C8F
-rw-r--r--  1 jonathanfilbert  wheel  4660684 Jan 17 19:50 App_175B9F9E-2372-4165-AA2B-F0123E12ABEB-1895-00000095CD045C8F.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb  6 15:28 App_17D25F31-21C7-4C55-97B4-278F3EF29F8B-1295-0000004E3FCB237E
-rw-r--r--  1 jonathanfilbert  wheel  4660684 Dec 25 00:10 App_17D25F31-21C7-4C55-97B4-278F3EF29F8B-1295-0000004E3FCB237E.tar.gz
drwxr-xr-x  3 jonathanfilbert  wheel       96 Nov 21 18:27 App_18987876-EDA5-44F8-839D-9D0ED9E85C10-1225-00000058DFD63585
-rw-r--r--  1 jonathanfilbert  wheel   331578 Nov 21 18:27 App_18987876-EDA5-44F8-839D-9D0ED9E85C10-1225-00000058DFD63585.tar.gz
drwxr-xr-x  3 jonathanfilbert  wheel       96 Dec  5 19:01 App_18CFA5BA-85C7-4EC0-930C-73A0847EA055-1197-00000056895B3D96
-rw-r--r--  1 jonathanfilbert  wheel   331578 Dec  5 19:01 App_18CFA5BA-85C7-4EC0-930C-73A0847EA055-1197-00000056895B3D96.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb  6 15:28 App_18E54EEA-52A5-4EE5-BC99-1D112C18A214-1352-00000051E2111EC0
-rw-r--r--  1 jonathanfilbert  wheel  4660684 Jan  7 15:44 App_18E54EEA-52A5-4EE5-BC99-1D112C18A214-1352-00000051E2111EC0.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb  6 15:29 App_1AB67930-C1CE-46E9-AB02-B6E24E0385B7-1223-00000051EB8F1D18
-rw-r--r--  1 jonathanfilbert  wheel  4660684 Feb  2 18:25 App_1AB67930-C1CE-46E9-AB02-B6E24E0385B7-1223-00000051EB8F1D18.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb  6 15:28 App_1AC8F899-D2AA-4AB9-9BF1-35BE98ED1EDE-16157-000006E2D274F110
-rw-r--r--  1 jonathanfilbert  wheel  4660684 Dec 21 19:17 App_1AC8F899-D2AA-4AB9-9BF1-35BE98ED1EDE-16157-000006E2D274F110.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Feb  6 15:28 App_1F263B6A-077E-482C-94FF-3C3D6892F2B9-1324-0000005F3A9C6E56
-rw-r--r--  1 jonathanfilbert  wheel  4660684 Jan 26 12:39 App_1F263B6A-077E-482C-94FF-3C3D6892F2B9-1324-0000005F3A9C6E56.tar.gz
drwxr-xr-x  3 jonathanfilbert  wheel       96 Dec  5 19:34 App_221EA77C-0E38-421F-9BF6-D5465E75EE63-2756-000000D9B2A9FFF6
-rw-r--r--  1 jonathanfilbert  wheel   331578 Dec  5 19:34 App_221EA77C-0E38-421F-9BF6-D5465E75EE63-2756-000000D9B2A9FFF6.tar.gz
drwxr-xr-x  2 jonathanfilbert  wheel       64 Mar 23 16:59 App_22BBCFA5-1384-4B28-9688-C5463795FD48-1143-0000006521EDAAE0
-rw-r--r--  1 jonathanfilbert  wheel   331578 Dec 17 23:39 App_22BBCFA5-1384-4B28-9688-C5463795FD48-1143-0000006521EDAAE0.tar.gz

Here is the ls -l results for some of the directories

-rwxrwxrwx  1 jonathanfilbert  wheel   244928 Jan 13 20:41 a_0058AB63-F619-42E5-BBA5-86532551CFA3-1193-00000054FCB20168
-rwxrwxrwx  1 jonathanfilbert  wheel   210848 Dec 23 15:51 a_0153215B-DE1E-47B0-B4DF-961804DB2CB2-1216-00000057AE7086FB
-rwxrwxrwx  1 jonathanfilbert  wheel   210848 Dec 17 13:00 a_01BDBE1A-5EDC-413E-BE41-33A611EF871F-1134-000000754A4E692A
-rwxrwxrwx  1 jonathanfilbert  wheel   210848 Jan  2 11:33 a_01F076CE-B02D-4C1F-8058-A4A832333CE7-1291-0000004D445928B5
-rwxrwxrwx  1 jonathanfilbert  wheel   210848 Dec 19 14:09 a_02B73853-967A-4723-98BA-D81553A2D7FE-1189-0000004EACDB9D9C
-rwxrwxrwx  1 jonathanfilbert  wheel   210848 Nov 11 15:30 a_036B3671-AF44-4439-9BA5-1B31232B6CE1-1243-0000004FA1CF7311
-rwxrwxrwx  1 jonathanfilbert  wheel   210848 Nov 17 19:08 a_06AEA1F5-2958-4AAB-A9FE-741837F4FCA9-1206-0000004E458C7071
-rwxrwxrwx  1 jonathanfilbert  wheel   210848 Dec  1 23:56 a_0880EF4F-ADF4-4DF5-A0F7-C5689828D5DC-9985-0000041F7999B6FA
-rwxrwxrwx  1 jonathanfilbert  wheel   244928 Jan 16 18:15 a_0898EB66-62FE-4D6A-8D60-E4EC2A2489E4-1178-000000541561A81E
-rwxrwxrwx  1 jonathanfilbert  wheel   210848 Dec  8 17:32 a_0ABD7D94-04C0-40FC-A637-01DB09630972-1233-0000004D07EB2930
-rwxrwxrwx  1 jonathanfilbert  wheel   210848 Dec  5 12:22 a_0D32C0E7-A993-47B1-A7C6-4D41C2B691E1-1160-0000005194510DAA
-rwxrwxrwx  1 jonathanfilbert  wheel   183456 Dec 25 00:10 a_0D3F7A43-9BB0-4D09-9811-6953AD28AE4D-1295-00000051353554A9
-rwxrwxrwx  1 jonathanfilbert  wheel   244928 Jan 29 21:33 a_0D5D220A-C3C0-49B7-A64B-49C64E3DD865-6976-000000680ED5309B
-rwxrwxrwx  1 jonathanfilbert  wheel   210848 Nov 10 23:11 a_1288DB46-490B-49D4-840F-3E725AF6F4AE-1243-0000006C70925320
-rwxrwxrwx  1 jonathanfilbert  wheel   244928 Jan 11 23:08 a_132D252F-B372-468B-A748-D084AEE5E355-1275-0000006BA6ED0EBA
-rwxrwxrwx  1 jonathanfilbert  wheel   244928 Jan 17 19:50 a_141E730D-6CE1-470B-86B9-8CABEF1F4A4C-1895-0000009B37EC280A
-rwxrwxrwx  1 jonathanfilbert  wheel   210848 Nov 25 23:53 a_1817CEF5-03C3-4968-8CA9-03F5D24540BF-1330-0000006C576DC205

My question is, aside from the 6 recognized folders, is it safe to delete those things? As they take up quite a lot of space, and recently, I found a malicious file named SystemExtr residing inside one of the folders, and deleted it, but somehow it returned.

Best Answer

Note: this doesn't answer your question directly but is advice and some further steps to troubleshoot.

If your computer has been reported as being affected my malware, you are likely better off long-term to back up your personal data (i.e user directory etc), note the apps you have installed, and start over with a nuke & repave. A few hours spent doing this is better than rescuing a system with unquantified levels of malware -- it could be just 'SystemExtr' or it could be a whole heap of other things -- and the nature of some malware means it can't be 100% removed.

In the meantime:

  • use a reputable macOS malware scanner like Malwarebytes or Sophos to see if they pick anything up;
  • upload one of the executables to VirusTotal to see if it find anything;

And for ongoing homework: learn a bit about hard drive space management and reduce reliance on the whizzy apps (especially the free ones) that do all this for you. Some are reputable, some are junk. Using a disk viewer like Grand Perspective will give you better visibility into what's going on inside your hard drive, and give you more control overall.

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