Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b9963db35dd26b3…

MALICIOUS

PDF

88.4 KB Created: 2021-07-19 08:07:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: d638ba3b0295a3b9e51f15ee974bb17a SHA-1: 9d0506b31d2fab3901129e5742fb12eb686cb01e SHA-256: 5b9963db35dd26b3200419aed294087b82af1e850fee16b8ba02b81e52c74bf7
156 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to numerous other PDF files hosted on compromised WordPress sites. This behavior is indicative of SEO manipulation or a distribution mechanism for further malicious content. ClamAV detected this file as 'Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0', and ML classifiers also flagged it as malicious. No scripts were extracted, but the structure suggests it's part of a larger campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/l7s83k5j6kbrcad9i1kqvhvko5/mamiloniza.pdf In PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/16081e801f34e0---14852224849.pdfIn PDF document text
    • https://www.escon.it/wp-content/plugins/super-forms/uploads/php/files/0e22941af602d13d192a22bdb16e7734/warokopuvi.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/d344b076f94e346dde07f36c394e9321/73949206991.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/fbb577170a757092e3e60bcf260caef5/30174465794.pdfIn PDF document text
    • http://jar-ted.pl/file/pawisaxodidor.pdfIn PDF document text
    • http://babamoleskine.com/files/file/tutaxegajimupikebowezasor.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/160bdf5e5a09fe---92153136105.pdfIn PDF document text
    • http://bezagsecurity.cz/userfiles/dovozimelamajopa.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160bd8d7f37322---rudoxapojisixomoziped.pdfIn PDF document text
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606c945d59ff2---pulonere.pdfIn PDF document text
    • http://payassistinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160985c8f870bb---tametadiborufovobobo.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fb22444398---11208775574.pdfIn PDF document text
    • https://coolingrealestate.com/your-home-cleaner/FCKuploads/file/supoviduzela.pdfIn PDF document text
    • https://foundryindia.org/userfiles/file/susabafipisevu.pdfIn PDF document text
    • http://ambvetsanprospero.eu/userfiles/files/97845763462.pdfIn PDF document text
    • https://rarahil.org.np/ckfinder/userfiles/files/nawumilotesedujuvoxovoles.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072c784033b9---64917512484.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160c6fe516c074---dakovi.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077cb6c1cade---13390480201.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/160be67584dc4e---27930631109.pdfIn PDF document text
    • http://apexibd.com/uploads/fck_uploads/file/22743639736.pdfIn PDF document text
    • https://perfecthospital.org/FCKeditor/file/12580296721.pdfIn PDF document text
    • http://tentimesneedlehill.com/UPFILE/userfiles/files/mazidetorovovexokigag.pdfIn PDF document text
    • https://mimpishio2bet.com/contents//files/78941544644.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=miniature+american+shepherd+puppies+for+salePDF 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_off0000f4a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4A4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010cbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CBB 10976 bytes
SHA-256: 87a10a92734ea57d17b627b9bed264f29de291e997adbc742543d08bfd3050e6
font_02_sfnt_off000125fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125FE 17464 bytes
SHA-256: 2d38e9e858b33089a59aa8c399ddd939df3c5e7a8bc9b326ce1dd6ebec3a86f0