Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7a7b81ce10601b3…

MALICIOUS

PDF

79.2 KB Created: 2021-06-12 14:56:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 3c2b9ad832d498d452baa7c970d26944 SHA-1: 02b5dcb1baeed5f2c1c1cba7eeb47c92b6a7a74f SHA-256: a7a7b81ce10601b322df7de0719c6253e73e7fe01e58e13744ff72a2a3ab677e
156 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs pointing to compromised WordPress sites, suggesting it's part of a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to contain junk data, further indicating malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://synerhu.ru/uplcv?utm_term=gmo+carrots+pros+and+cons PDF link annotation
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/vf5149m3kf1ff9mk5mjkmcqd8m/figadigipuxofub.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607934436e6d7---95326243330.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b30beea8909---91279628335.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7266389535---nerukelebafofon.pdfIn PDF document text
    • http://isystem.hu/ckfinder/userfiles/files/sozulaganevukobexesizelis.pdfIn PDF document text
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/549ff2656bcf232138c531d600f799c2/mixuvanabeziliviromodido.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160826cb65b555---vamijibovibelezuke.pdfIn PDF document text
    • https://sarujiovalente.com/wp-content/plugins/super-forms/uploads/php/files/t58984sgcb1g5pec13rgj7o871/67451710182.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609863c4c5c77---raloxosatiguve.pdfIn PDF document text
    • http://jarosi.hu/files/file/55475033823.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f7c8f37767---zigoxojolav.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609746296beaa---pilazubavisesogog.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/tus4i7gpdlps055nrvi4ao57fi/pigedopabolonovex.pdfIn PDF document text
    • https://www.lightingdynamics.com/wp-content/plugins/super-forms/uploads/php/files/5978130b893f91d19415e5013d5d4f41/67752533821.pdfIn PDF document text
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/a66815332714a73210ddd24e048762b7/6898027325.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fb9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB9E 5216 bytes
SHA-256: 24747219a80f32e7e6fbe7d46c1c1810b4eae3967a4ab2f4ffe8c3669b1b8061
font_01_sfnt_off00010d46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D46 10260 bytes
SHA-256: 4505536ced91f0de42013b0b63cc3b363a5de33a80f41d8310af0020d48f177b