Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb1f637761b91b58…

MALICIOUS

PDF

79.2 KB Created: 2021-09-08 00:47:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: db3a88b584a7ee327659d57586240b58 SHA-1: 9b0d3950f37a9130e30dba3bd8c2a5987bd2dfd9 SHA-256: cb1f637761b91b5843dbfb9e668d2ef83acab904a34a23f4f9feee0429b3977d
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF was flagged by ML classifiers and ClamAV as malicious, exhibiting characteristics of a callback phishing or tech-support scam. The document body, though heavily obfuscated, contains embedded URLs that point to compromised CMS uploads and disposable hosting, suggesting an attempt to host malicious content or redirect users. The presence of multiple PDF-specific heuristics further supports its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://acpiindia.com/userfiles/file/53132189768.pdf In PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/lenuvidefe.pdfIn PDF document text
    • https://www.jscorporation.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/1609d0f1fe5c3c---suvajoxeluzoxulexu.pdfIn PDF document text
    • http://happyhanool.com/ckupload/files/limololure.pdfIn PDF document text
    • http://www.dgtrans.co.th/login/ckfinder/userfiles/files/vovaxifa.pdfIn PDF document text
    • http://mextro.de/upload/files/napufusote.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612510c9aa9c9---losakubonubejafaluj.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/sizudo.pdfIn PDF document text
    • http://stefani.cz/fck/file/puzulovulebofavaluketoko.pdfIn PDF document text
    • https://www.bakkersvlaanderen.be/resources/plugins/ckfinder/userfiles/0/files/99699902146.pdfIn PDF document text
    • http://cementfeet.com/userfiles/file/napebanelipek.pdfIn PDF document text
    • https://uleshuzataruhaz.hu/files/file/bevufozuvixedif.pdfIn PDF document text
    • http://goref.ru/files/file/14750653337.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6706cc4b58---luvabegekekezubaw.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160c68f6618698---78350498534.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/1607b74d051c3f---56175283661.pdfIn PDF document text
    • http://bpabv.nl/uploadfiles/file/19756604101.pdfIn PDF document text
    • https://penzionradvanice.cz/res/file/wuwefukujopaboxupimop.pdfIn PDF document text
    • http://diysmart.net/userfiles/file/lafezimalujovusuv.pdfIn PDF document text
    • http://dr-onesrl.com/userfiles/files/wamosuvesowedipa.pdfIn PDF document text
    • http://tmkb.org.tr/ckfinder/userfiles/files/tuvaleranesuwe.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b284853a1b7---roxidaxigegawobomir.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160d4dc83b75e5---24785485125.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/5ced1e69fc11c371074703ca30e64a20/valudosewakiniridi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=authentication+vs+authorization+pdfPDF 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_off0000cf4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF4F 17852 bytes
SHA-256: c0fffe9e95d3275eb7625ee3f307e26f264c34a33626d7106f2a201f204a6e95
font_01_sfnt_off0000fdc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDC9 10876 bytes
SHA-256: d435d41366af04eb72ca5199f6d87d3b10079bb1a0cb5b9ccdebeb13dc053923
font_02_sfnt_off00011700.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11700 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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