Malicious PDF — malware analysis report

Static analysis result for SHA-256 c28b257daa1d71c1…

MALICIOUS

PDF

83.8 KB Created: 2021-09-04 04:52:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 79d4712a06b6ad35e6500cdb80cb0972 SHA-1: 518311c66d898c689472ed2c55073363851a36b5 SHA-256: c28b257daa1d71c103a0b4e8ff9a105ed4aa331145079206fc2b2cd76d592a57
156 Risk Score

Malware Insights

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

The PDF document contains numerous links, many of which point to compromised WordPress sites and disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16081009af3fb1---3214795635.pdf In PDF document text
    • https://ferropula.hr/files/bibakisudorokinurawugo.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/zivalofobuxomidemewir.pdfIn PDF document text
    • http://mfcwestenkwartier.nl/beta/userfiles/file/80293928127.pdfIn PDF document text
    • http://unternehmensberatung-hegenbarth.de/userfiles/file/20670961136.pdfIn PDF document text
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/879ca96e1b11b179c11d645d44b42719/89255409201.pdfIn PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/c5ebf2c4c2c7683cc84d34ef3f7d7369/folexawozixazol.pdfIn PDF document text
    • http://popnmusic.fr/userfiles/file/nedapokalukevuviraxufa.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d00a19057---roxeposupog.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ce2e5a28f85---musozifufetefexofubowe.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a390e3ad8f---78673655163.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608f8320c6e06---kexexonuto.pdfIn PDF document text
    • https://cls-toronto.com/wp-content/plugins/super-forms/uploads/php/files/616c36c412f7478978f64d8456ed1a58/sunoxabe.pdfIn PDF document text
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/caaf1a375f5ddba0f4ba41f7b42e5cdd/93513063317.pdfIn PDF document text
    • http://kondicionery-fryazino.ru/upload_picture/file/gawavewiroxekosat.pdfIn PDF document text
    • http://bajcsidavidfoto.com/_user/file/netigidi.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/59v92u3ihu8olad7kon664l5l4/lufewizilotiwobokato.pdfIn PDF document text
    • https://cplastik.cz/data/cms/file/sotamuzexoxovikobiw.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e4c4e22c42---ribawexavewopelo.pdfIn PDF document text
    • http://randoquad72.fr/userfiles/file/semanimeg.pdfIn PDF document text
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a080071d4b3---22869302967.pdfIn PDF document text
    • http://cablexconsulting.com/Upload/file/53074877515.pdfIn PDF document text
    • http://awkontrakt.pl/ckfinder/userfiles/files/6874765089.pdfIn PDF document text
    • https://irepairplus.nl/app/webroot/files/userfiles/files/77820872765.pdfIn PDF document text
    • https://walnutcreekguide.com/wysiwygfiles/file/38523288309.pdfIn PDF document text
    • https://partnyor.az/userfiles/file/fafibafebezufogovatofi.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/7idh940ejet1l95717cnk90gkq/22304357184.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=musicianship+level+1+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_off0000de21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE21 19104 bytes
SHA-256: 7aab11b64c4bdef831ffa9132306478700530b6ccb6ee4a7b27966764cbdf8ee
font_01_sfnt_off00010fb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FB9 10608 bytes
SHA-256: e85006c0ba1a838e70d76730e7d1c67ebd289f71fb176b6a4228cfc21c2d76f4
font_02_sfnt_off000127ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1