Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5177ad6810fab0a…

MALICIOUS

PDF

68.9 KB Created: 2021-10-02 21:52:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 15abc529f6713b13c0b5f4eeee5c4ecf SHA-1: afa9093ff473056dea53ead126d8576744f60279 SHA-256: a5177ad6810fab0aa92ccb079d36b0e261bd9fcfb834a9fb8f5dbcf547a7e72b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links pointing to compromised WordPress upload directories and other disposable hosting, suggesting a link farm designed to redirect users to malicious sites. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/16143730a81666---kabiriwuponetifimugipok.pdf In PDF document text
    • https://unitedfightalliance.com/ckfinder/userfiles/files/towuvisamew.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210904000702.pdfIn PDF document text
    • http://workontext.ru/media/file/59959135559.pdfIn PDF document text
    • https://cfaegaianascente.pt/portal/userfiles/files/seben.pdfIn PDF document text
    • http://glendale.kopanramen.com/uploads/files/folejur.pdfIn PDF document text
    • http://bajkolandia-leszno.pl/userfiles/file/kemipazerogutakusudis.pdfIn PDF document text
    • https://rowsontw.com/shopadmin/upload/files/weviratoj.pdfIn PDF document text
    • http://air-separation-supplier.com/d/files/sitisoviv.pdfIn PDF document text
    • http://artstudiodesign.it/userfiles/files/6300188670.pdfIn PDF document text
    • http://biznesfishki.ru/files/userfiles/files/97324024772.pdfIn PDF document text
    • http://fst-uinsu.net/userfiles/files/gezojomukalebigubagexe.pdfIn PDF document text
    • https://canoe.ro/Extras/ckfinder/userfiles/files/48842583667.pdfIn PDF document text
    • http://zjhywt.com/images/upload/File/26436973087.pdfIn PDF document text
    • https://bellcera.60km.com/upload/files/jokuwapiletiroxuj.pdfIn PDF document text
    • http://prosefkuchare.cz/userfiles/84331531741.pdfIn PDF document text
    • http://proficlim.ru/public/userfiles/file/63521697784.pdfIn PDF document text
    • https://pre-www.bridge-college.com/uploaded/ckeditor/files/9251456321.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e478b74a06---pupubasetumujibu.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c971ed1926---31747154091.pdfIn PDF document text
    • http://1day2night.com/UserFiles/file/kobunedupuduz.pdfIn PDF document text
    • http://kientrucphatloc.com/upload/files/fuburuwadalegofilinoxup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=meatballs+and+cocktail+wieners+in+crock+potPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000acf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xACF8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c50f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC50F 10820 bytes
SHA-256: 4c96c9d7afabd5166e3551a382b0d9afc8ec20d319e71c4eec49fc710c5e98e7
font_02_sfnt_off0000ddfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDFB 15376 bytes
SHA-256: 2a6aa324436f6b44b6c10875950f037d64f1763d9db626f373eb536fc97587b6