Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 657800d3fdb7f78f…

MALICIOUS

Office (OLE)

318.5 KB Created: 2020-07-10 10:41:45 Authoring application: Microsoft Excel First seen: 2020-09-07
MD5: b6c5a6c866b40d384cdd898cbe343db3 SHA-1: 8debe08786d92689f501ceca3879d315935bccb8 SHA-256: 657800d3fdb7f78f79c64d1a03ab93413dafe92cf31fe00a9003762b1cb35df5
242 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample is an Excel 4.0 macro-enabled spreadsheet that contains an Auto_Open macro. Heuristics indicate the document uses a lure to enable macros, impersonating a signing service. The XLM macro sheet contains a reference to the Auto_Open function, which is a common technique for executing malicious code upon opening the document. The macro likely downloads and executes a second-stage payload, as suggested by the 'Dropper' detection from ClamAV.

Heuristics 7

  • ClamAV: Xls.Dropper.Agent-8899085-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Agent-8899085-0
  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • Document signing service impersonation lure medium SE_DOCUSIGN_LURE
    Document impersonates DocuSign, Adobe Sign, or a similar signing service in a signing-request context
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.w3.org/1999/02/22-rdf-syntax-ns# In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/mm/In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 70364 bytes
SHA-256: 396c206f9f01c57845193978a72b6a945c31f17c44de5c08cc879f01543f086d
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, very hidden -  Sheet
' 0085     10 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  G
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0018     16 LABEL : Cell Value, String Constant - a len=0 
' 0018     31 LABEL : Cell Value, String Constant - agcoFGbdmKqUkRXq len=0 
' 0018     58 LABEL : Cell Value, String Constant - aIKfIMaWFTssTcoRkQnGfGRLdMjTdjfrIXegpNIlnUa len=0 
' 0018     34 LABEL : Cell Value, String Constant - aIwRHxMWFFrrTboQkPn len=0 
' 0018     53 LABEL : Cell Value, String Constant - aJJvvXfsUoTrJVKHBTQnXhnjvMNiktRxbrYexG len=0 
' 0018     53 LABEL : Cell Value, String Constant - aKUaWiyzVXgElPeLRksiOJKINxqxcDoFILDbFj len=0 
' 0018     44 LABEL : Cell Value, String Constant - atNgbQvFGEJtnuYlkBFHyYnfQxzVx len=0 
' 0018     53 LABEL : Cell Value, String Constant - atZxPpPbVnWscntpBShopzXSvxdkELBgbcafRX len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!N25468 
' 0018     52 LABEL : Cell Value, String Constant - bcafRKRuWHXbeVuXDmiXrhYmwffSFfCPdLcOS len=0 
' 0018     54 LABEL : Cell Value, String Constant - bDMYzUyXpBpmgyvTDNTPbrsOQZwdHXEKdlaGCCB len=0 
' 0018     59 LABEL : Cell Value, String Constant - BeGqHLOFeHmWSGbRIWgPPCoPlyNuMxCbQNHZWsPntpBF len=0 
' 0018     23 LABEL : Cell Value, String Constant - bEJWTCPo len=0 
' 0018     54 LABEL : Cell Value, String Constant - BFHyYBfQMzULCQaJIviJfrGnFrvVJHBTQmJhnju len=0 
' 0018     58 LABEL : Cell Value, String Constant - bgRKSvJIYceWvLDnVXrUZnxSfTGgDCeLcPTsTeYqnKg len=0 
' 0018     43 LABEL : Cell Value, String Constant - BJKTqlPRxEXfVBvwuzkryPppFuxp len=0 
' 0018     45 LABEL : Cell Value, String Constant - BqWffejUNUyMLbehZxNGpYauXcpzVi len=0 
' 0018     32 LABEL : Cell Value, String Constant - BRUXPnRvfbQkbSfpZ len=0 
' 0018     59 LABEL : Cell Value, String Constant - BtBfsrILOGetmWFHbEJWgCPDoQmlNuMxCcDOIaXtPogc len=0 
' 0018     63 LABEL : Cell Value, String Constant - BuNwTDOUQbsHPQaxsWXELdlbHCDBGqxFVwvMCFvVxdaJwSIy len=0 
' 0018     41 LABEL : Cell Value, String Constant - CDjEJRHmvwuzXdkPcbruxpPdWH len=0 
' 0018     59 LABEL : Cell Value, String Constant - cdyzJhOrHntNVLqlmkpaTbFgRhlnfFhMwsgCriwHppcP len=0 
' 0018     54 LABEL : Cell Value, String Constant - CeiwsbpOPpyLnHmKcCcnhziGpzGCOetBDMjeIKq len=0 
' 0018     24 LABEL : Cell Value, String Constant - CFUpqBKFi len=0 
' 0018     54 LABEL : Cell Value, String Constant - cllkpaTaFSRhknfETMvegBdivGbocOpMLmUlXbC len=0 
' 0018     54 LABEL : Cell Value, String Constant - cnhzwToNGCNetPCMjeIKpKQXNsCDBGdjqVihxBE len=0 
' 0018     20 LABEL : Cell Value, String Constant - COqKp len=0 
' 0018     31 LABEL : Cell Value, String Constant - CQauJviJfeHnFrvV len=0 
' 0018     49 LABEL : Cell Value, String Constant - czSrSdXpZvfqvsEVjrsCaVxzgmGOEjefdi len=0 
' 0018     63 LABEL : Cell Value, String Constant - DEZbkIpTiPVowmSNOMRCuCgHsJMPHfJnYTIcTKXhRQEpRnzO len=0 
' 0018     45 LABEL : Cell Value, String Constant - DKRvIIXbeWuKDmUXrUYmjSfFFgoBdw len=0 
' 0018     33 LABEL : Cell Value, String Constant - DlZtkbpzihVVwFRtNs len=0 
' 0018     26 LABEL : Cell Value, String Constant - dMOiLPdnJWJ len=0 
' 0018     50 LABEL : Cell Value, String Constant - DNvviiKSfHaGevIwtnGDZJUaWhyzVWgEkOe len=0 
' 0018     43 LABEL : Cell Value, String Constant - dNYdZlDEZajIoShOUnvlRMNLQBtB len=0 
' 0018     46 LABEL : Cell Value, String Constant - DrMDtHRzznnOXjMfLiBNBxrKIeOYeam len=0 
' 0018     59 LABEL : Cell Value, String Constant - dxMylMihKqJuyYyKEWTpMkcYkBQlZiGBegNhmukQYZXc len=0 
' 0018     36 LABEL : Cell Value, String Constant - DZvUaWhkzVWgpkOdwQjeT len=0 
' 0018     64 LABEL : Cell Value, String Constant - eGFVLNFeHljSGbRIWgPPCCdlyatZxPbPNHZWscntpBSTopzXE len=0 
' 0018     31 LABEL : Cell Value, String Constant - eGqHLNFeHlWSGaRI len=0 
' 0018     28 LABEL : Cell Value, String Constant - EkqKSHmiihlXQ len=0 
' 0018     36 LABEL : Cell Value, String Constant - ELoCBRVYPoEwgORlOSgcL len=0 
' 0018     27 LABEL : Cell Value, String Con
... (truncated)

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