Malicious PDF — malware analysis report

Static analysis result for SHA-256 77a5853e095263bc…

MALICIOUS

PDF

107.9 KB Created: 2021-08-17 05:02:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 04e15351373c40c129e063ac071b7447 SHA-1: 8dab7363bbb61884631c5f217430a8a039ed70d8 SHA-256: 77a5853e095263bce6861d57ef7989b1fac4fc4652617e7d1232ef55c93bfc93
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or are part of a link farm hosted on disposable domains. These URLs are likely used to redirect users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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 https://sbsoftware.ro/admin/userfiles/file/50396768633.pdf In PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/5qi3fj171rbet9ari3e3i8vmq6/fizorozu.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16082b72f71062---42107079152.pdfIn PDF document text
    • https://mtestbd.com/assets/uploads/files/fotitukor.pdfIn PDF document text
    • http://csc-021.com/userfiles/file/20210621110628_7hh4gr.pdfIn PDF document text
    • http://bestcareloan.com/ckupload/files/fanomi.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/44esf10sh6rc05at8uhv7cb1bm/goxudelupuwedadidogawin.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ff8cf6acec---gabevebesowudu.pdfIn PDF document text
    • https://stka.gr/ckfinder/userfiles/files/45779961455.pdfIn PDF document text
    • https://www.icslights.com/wp-content/plugins/super-forms/uploads/php/files/59d0d43b1e7afea9ec592a8f56947dd3/39695182535.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/8fef89f1bf4d1624e510add5fdc750b0/korixizupexegedunenit.pdfIn PDF document text
    • http://thoitrangvabaoho.com/Images_upload/files/wuremikapisamofagape.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f288107ea4---doleremufofenirarolojopuv.pdfIn PDF document text
    • http://biosafety.biz/ckfinder/userfiles/files/74939094958.pdfIn PDF document text
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/a073e499a549f80f6e0014c6d9310294/4686562550.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16092bc009c6b5---vagab.pdfIn PDF document text
    • http://digilit.ir/basefile/digilitir/files/mimilekofovezevaxokij.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b0ccf8b6fc---fofakupuvuro.pdfIn PDF document text
    • http://cheapneasytrafficschool.com/CheapNEasyTrafficSchool/pa/trainstation/uploads/image/file/74050332893.pdfIn PDF document text
    • http://feg.vn/uploads/files/fedovalegavunuxip.pdfIn PDF document text
    • http://abwingstop.com/uploads/files/dupedamelidegodiribuw.pdfIn PDF document text
    • http://omatsuri.kr/data/userfiles/files/duzofeletixiwofeboxolu.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-5-17/20210517064751150497.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/d36e4974c49bf9b6fcda13e68443851d/3020100439.pdfIn PDF document text
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/g6vno0qt6pfqf5qp8kaqri9me8/sekorimonigomoveja.pdfIn PDF document text
    • http://www.courtesyparIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=350z+field+service+manualPDF 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_off00013f0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F0B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00015722.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15722 10976 bytes
SHA-256: dc306ab4d9befc59f528f3e613224e8a54f35617ef2bec99790df6e54f28152e
font_02_sfnt_off0001709d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1709D 18208 bytes
SHA-256: 72e255df855887e1bf24e65e4231035a0389531c4b51621edd27b72244b3e6b7