Since yesterday I've had multiple detections of the malware below - only on Exchange 2013 mailbox database servers. Two CAS servers are not showing anything, nor are any other AD-joined servers (so I don'tthink this is something spreading across the network).
I think these detections may be happenning because somehow a mail message with something bad in it has got past the mail filtering system and into a mailbox. I'm not sure why that would be popping up outside the mailstore DB as discrete files on the C drive.
I'm wondering if it's because of some kind of background Exchange optimisation process? As far as I know, no mailbox moves or exports were running at any of the times when this stuff was detected - I've seen references to similar experiences from other people
in various forums online, but without any definitive answers.
Antimalware is System Center Endpoint Detection on Server 2012 R2.
Can anyone explain the processes that might be going inside Exchange that would cause stuff to be pulled out of a mailbox and onto the C drive? I need to rule out if these servers are actively being attacked over the network by something.
I have put the (licenced) business version of MalwareBytes onto one of the servers in addition to SCEP and it detected nothing. A full scan from SCEP also detected nothing.
Further, if this is some item with nasty attachments sat in a mailbox, how can I identify and remove it? Can that be found in a log somewhere, or are there commercial products that can scan the contents of the mailstores (as opposed to scanning stuff as
it passes into and out of Exchange).
Thanks for any help.
Here's the detail:
Trojan:Win32/Skeeyah.A!rfnSevereTrojan
Detected in:
C:\Windows\Temp\OICE_386F84D7-B003-432B-9DCE-727112BB940F.0\FLT83AE.tmp1
C:\Windows\Temp\OICE_DA89E288-4D74-4F8C-908D-F0A33516684D.0\FLT9C5C.tmp1
C:\Windows\Temp\OICE_DA89E288-4D74-4F8C-908D-F0A33516684D.0\FLTA92E.tmp1
C:\Windows\Temp\OICE_956671F3-3EB5-4819-AB2C-B5D0B4ABF691.0\FLTBDF6.tmp1
C:\Windows\Temp\OICE_956671F3-3EB5-4819-AB2C-B5D0B4ABF691.0\FLTB6A2.tmp1
C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\data\Temp\UnifiedContent\1d9ccefc-e1ff-4f2d-9ff6-ba633871fa2a->Files/Graph1/YNKZJ2~1.EXE1
C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\data\Temp\UnifiedContent\1d9ccefc-e1ff-4f2d-9ff6-ba633871fa2a->Files/Graph1/71912-pcs2r8z8e45tex8850ajzny103irbdko6f_ykxa5jxkfkcuc608onw4xefsfnv_x.exe1
C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\data\Temp\UnifiedContent\1d9ccefc-e1ff-4f2d-9ff6-ba633871fa2a->Files/Graph1/3207-id_N287_wp_enc_x32_2018-09-13_21-37.exe1
C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\data\Temp\UnifiedContent\1d9ccefc-e1ff-4f2d-9ff6-ba633871fa2a->Files/Graph1/1GEJJB~1.EXE1
C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\data\Temp\UnifiedContent\1d9ccefc-e1ff-4f2d-9ff6-ba633871fa2a1
C:\Windows\Temp\OICE_F1ABB43B-924F-460C-864C-D7E960EC16BF.0\FLTEEFA.tmp1
C:\Windows\Temp\OICE_7EDB0BA0-88B2-4EB0-BB39-748E3B7AB6E3.0\FLTFAE1.tmp1
C:\Windows\Temp\OICE_7EDB0BA0-88B2-4EB0-BB39-748E3B7AB6E3.0\FLTEFC4.tmp1
C:\Windows\Temp\OICE_7EDB0BA0-88B2-4EB0-BB39-748E3B7AB6E3.0\FLT4A9.tmp1
C:\Windows\Temp\OICE_727D89F6-5CE5-43D5-89DC-58ED5D39902B.0\FLTCABB.tmp1
C:\Windows\Temp\OICE_727D89F6-5CE5-43D5-89DC-58ED5D39902B.0\FLTC1F0.tmp1
C:\Windows\Temp\OICE_629813AC-0B76-42D3-AC13-2B4CB16FC5D6.0\FLT866E.tmp1
C:\Windows\Temp\OICE_629813AC-0B76-42D3-AC13-2B4CB16FC5D6.0\FLT8360.tmp1
C:\Windows\Temp\OICE_DA89E288-4D74-4F8C-908D-F0A33516684D.0\FLTEC15.tmp1
C:\Windows\Temp\OICE_DA89E288-4D74-4F8C-908D-F0A33516684D.0\FLTF108.tmp1
Trojan:Win32/MereTam.ASevereTrojan
Detected in:
C:\Windows\Temp\OICE_629813AC-0B76-42D3-AC13-2B4CB16FC5D6.0\FLT8AC7.tmp
1
C:\Windows\Temp\OICE_727D89F6-5CE5-43D5-89DC-58ED5D39902B.0\FLTD08A.tmp
1
C:\Windows\Temp\OICE_7EDB0BA0-88B2-4EB0-BB39-748E3B7AB6E3.0\FLT44A.tmp
1
C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\data\Temp\UnifiedContent\1d9ccefc-e1ff-4f2d-9ff6-ba633871fa2a
1
C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\data\Temp\UnifiedContent\1d9ccefc-e1ff-4f2d-9ff6-ba633871fa2a->Files/Graph1/40917-44783m8uh77g8l8_nkubyhu5vfxxbh878xo6hlttkppzf28tsdu5kwppk_11c1jl.exe
1
C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\data\Temp\UnifiedContent\1d9ccefc-e1ff-4f2d-9ff6-ba633871fa2a->Files/Graph1/eoHzaMC.exe
1
C:\Windows\Temp\OICE_DA89E288-4D74-4F8C-908D-F0A33516684D.0\FLTB017.tmp
1
C:\Windows\Temp\OICE_956671F3-3EB5-4819-AB2C-B5D0B4ABF691.0\FLTC397.tmp
1
C:\Windows\Temp\OICE_DA89E288-4D74-4F8C-908D-F0A33516684D.0\FLTF4C4.tmp
1
TrojanDownloader:O97M/Dornoe.A!amsSevereTrojan Downloader
C:\Windows\Temp\OICE_629813AC-0B76-42D3-AC13-2B4CB16FC5D6.0\FLT8AB6.tmp
1
C:\Windows\Temp\OICE_727D89F6-5CE5-43D5-89DC-58ED5D39902B.0\FLTD02C.tmp
1
C:\Windows\Temp\OICE_7EDB0BA0-88B2-4EB0-BB39-748E3B7AB6E3.0\FLT3CC.tmp
1
C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\data\Temp\UnifiedContent\1d9ccefc-e1ff-4f2d-9ff6-ba633871fa2a
1
C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\data\Temp\UnifiedContent\1d9ccefc-e1ff-4f2d-9ff6-ba633871fa2a->Files/Graph1/Customer Invoice.msg->(Ole Stream 2)
1
C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\data\Temp\UnifiedContent\1d9ccefc-e1ff-4f2d-9ff6-ba633871fa2a->Files/Graph1/Invoice_No_T4847.doc
1
C:\Windows\Temp\OICE_DA89E288-4D74-4F8C-908D-F0A33516684D.0\FLTAFA9.tmp
1
C:\Windows\Temp\OICE_956671F3-3EB5-4819-AB2C-B5D0B4ABF691.0\FLTC367.tmp
1
C:\Windows\Temp\OICE_DA89E288-4D74-4F8C-908D-F0A33516684D.0\FLTF4A4.tmp
1