Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ca8f34cd33cf237…

MALICIOUS

PDF

89.2 KB Created: 2021-09-19 08:21:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 965071fbb4e80ec2c93c3e7eab422c04 SHA-1: e19ae68ddf731d22898e2549f18c00cf5bb45660 SHA-256: 4ca8f34cd33cf237cfbfeddac845a1272b0e3c3492dbeda48c98e780fba6354c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF document identified as malicious by ML classifiers and ClamAV. It contains a link farm with numerous URLs, many hosted on compromised WordPress sites, suggesting an attempt to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a tactic to obscure the true destination and leverage compromised infrastructure. No scripts were extracted, but the overall structure points to a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/f45d85f6d86932870b9ea8b7f0b357af/56774659281.pdf In PDF document text
    • http://ibshop.gr/uploads/_uploads/files/49862097324.pdfIn PDF document text
    • http://mikomisushiwc.com/uploads/files/14840872447.pdfIn PDF document text
    • http://wyadonline.com/userfiles/file/44902619119.pdfIn PDF document text
    • http://smart.sut.ac.th/tsme/src/lib/ckfinder/userfiles/files/709783921.pdfIn PDF document text
    • http://issaproject.com/app/views/panel/ckfinder/userfiles/files/90320389525.pdfIn PDF document text
    • http://captaincook.hu/userfiles/file/60985773953.pdfIn PDF document text
    • https://jogamiskolc.hu/ckfinder/userfiles/files/16446225106.pdfIn PDF document text
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/dmto0808f1bjoaene63b5q37v1/5420851129.pdfIn PDF document text
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/qd2iheg1vchufqttstuckbse4g/42277911722.pdfIn PDF document text
    • http://orkoien.com/userfiles/files/pugivofupefeju.pdfIn PDF document text
    • https://akvanova.ru/sites/default/files/dokewatupezitavisubive.pdfIn PDF document text
    • https://coil.hk/upload/files/fuxinizanefogifarafoz.pdfIn PDF document text
    • https://krainaogrodow.eu/zdjecia/fck/file/welobafisifiloweridir.pdfIn PDF document text
    • https://rais.bg/uploads/file/96455985917.pdfIn PDF document text
    • https://samsungklimalar.com/upload/ckfinder/files/35713856542.pdfIn PDF document text
    • http://art-wonders.com/ckeditor/ckfinder/core/connector/php/uploads/files/75902812504.pdfIn PDF document text
    • http://craftland.de/res/wysiwyg/file/47320100956.pdfIn PDF document text
    • https://hunglivet.com/uploads/files/202109180207434855.pdfIn PDF document text
    • http://exhibitionchannel.com/upload/96349209231.pdfIn PDF document text
    • http://www.hzkontejnery.cz/ckfinder/userfiles/files/muxavakisune.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/e7f0c51f405484145a5786e3392b75aa/wovezevetexuzipiki.pdfIn PDF document text
    • https://prestinieurope.com/userfiles/files/tijegojexivofebufa.pdfIn PDF document text
    • https://salvatoredivilio.it/userfiles/file/97574553553.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=airpods+2+battery+life+androidPDF 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_off0000f740.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF740 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010f57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F57 10848 bytes
SHA-256: f71bd2315be1c0ab6555e4479a9968d01f2a7be4efe2e501b440efabb4b7ce8c
font_02_sfnt_off00012857.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12857 18196 bytes
SHA-256: 42331f50be6d8476a59bb469384caa6f793e9dd32a634c1d844616cb6a84a599