Malicious PDF — malware analysis report

Static analysis result for SHA-256 d336867fbac7b5f5…

MALICIOUS

PDF

76.4 KB Created: 2021-09-13 22:44:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 1da7e7ec8c8c9386f0e75f6e11a5c967 SHA-1: b43ced8e9929fc1144f8e970fafb34e1fbaa7be1 SHA-256: d336867fbac7b5f56cdcd7df57437bbfd14193b4a7500d0e132c5d8de4e9ae26
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing further malware. The document body is heavily obfuscated and unreadable, suggesting it's not intended for human consumption but rather to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://www.abandassociates.com/ckfinder/userfiles/files/kaposolaw.pdf In PDF document text
    • http://bertoniamministrazione.it/bertoni/public/file/15447431075.pdfIn PDF document text
    • http://phukientubepxinh.info/gomsu/sanpham/anh/files/xinunakejuzegutup.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/161382bdbdf0b5---buzubixibitamo.pdfIn PDF document text
    • https://astdubai.co/userfiles/files/887423170.pdfIn PDF document text
    • http://naturabliskociebie.pl/userfiles/file/jakegomutebetusiwalolinap.pdfIn PDF document text
    • https://www.weldcor.ca/public/ckfinder/userfiles/files/29856124282.pdfIn PDF document text
    • http://tubietelbar.hu/uploadfile/80858631856.pdfIn PDF document text
    • http://kraemer-duennebacke.de/files/file/76592054163.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613d07bbd496e---12341973423.pdfIn PDF document text
    • http://dydlhx.com/upfiles/file///kalakososudus.pdfIn PDF document text
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/97a1a6e648eaea9675012cb5c673acd5/netururi.pdfIn PDF document text
    • https://letajicikoberce.cz/userfiles/file/vinoke.pdfIn PDF document text
    • http://changrung.com/ckfinder/userfiles/files/71508746631.pdfIn PDF document text
    • http://psychologyforeverybody.com/ckfinder/userfiles/files/legus.pdfIn PDF document text
    • http://bulmarconsult.com/files/96880652236.pdfIn PDF document text
    • https://panama4d.com/contents/files/ninasogidafuliduzovowunir.pdfIn PDF document text
    • http://wakabaeducation.com/userfiles/file/85845435571.pdfIn PDF document text
    • https://dusunceokulu.net/resimler/files/sofokamenoxulegaxefunub.pdfIn PDF document text
    • https://agrocare.ro/ckfinder/userfiles/files/2245568845.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613be788d0c3f---92306451764.pdfIn PDF document text
    • https://doanhnghiepvietnam.niengiamdoanhnghiep.vn/img_duhoc/files/54361851837.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=potty+racers+4+hackedPDF 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_off0000c88c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC88C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e09e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE09E 16808 bytes
SHA-256: 80b0e33a395343d58ef4a7c83c782140378443df58cea7ba44f5bed4176d644e
font_02_sfnt_off00010bdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BDB 10508 bytes
SHA-256: 9d476b48aa0ffa59c044ff9f25898f52703123b66352feec5d15541f258b0911