Malicious PDF — malware analysis report

Static analysis result for SHA-256 35cfb37ec2a80276…

MALICIOUS

PDF

75.6 KB Created: 2021-09-04 08:03:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 865ead9d51b725332d99f82c59fae246 SHA-1: 0b5a1ab6db2015a2c6f2673a11f8255cb9ae0354 SHA-256: 35cfb37ec2a80276718218261749f2c13248c46be3c362df400025f8da58ead8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of links, many pointing to compromised WordPress sites hosting other PDFs. This structure suggests the primary purpose is to act as a link farm, potentially for phishing or distributing further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://telorgabus.com/contents/files/vapomunorefubo.pdf In PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b16417efc30---3630933309.pdfIn PDF document text
    • http://noithatnhapkhaugiasi.com/luutru/files/gorodudododokigalifido.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/4f032f30cf9f336341e7b74aef629c52/dewabopaxazuzatubi.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/gk7nmqbmfk36mb7de788li7s6d/witonovafizogi.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/4a194d9d71d2b6caf6ef05bc660b66db/47519743143.pdfIn PDF document text
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/34d0a9c0f093aaf0e461ced253a88951/ketug.pdfIn PDF document text
    • https://zanhotel.ro/beficientconsultingFiles/file/zidumuvopukolalu.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1607dd858d9a06---bijirexexeve.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089ce92efc13---74032965962.pdfIn PDF document text
    • http://tecs4.com/intranet/ckfinder/userfiles/files/xupijil.pdfIn PDF document text
    • http://dioceseofniranam.org/userfiles/file/bepar.pdfIn PDF document text
    • https://tl-systems.hu/files/files/62290522876.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c780c8915e0---gijakujizuzeti.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16119f016321d8---26939245679.pdfIn PDF document text
    • http://nebovsem.ru/app/webroot/files/files/14165068208.pdfIn PDF document text
    • http://eunlocker.com/Images/Editor/file/sivixafawatiseti.pdfIn PDF document text
    • https://cls-toronto.com/wp-content/plugins/super-forms/uploads/php/files/5835223b9f5811b0a47ef2f86ef7d6b0/bujigapiwe.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/16081c01376717---6840482575.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/87s5edfgnaj853pa0ka0csvtn5/digogotapiraxasif.pdfIn PDF document text
    • http://kerrya.com/ckfinder/userfiles/files/90158447731.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/933dff681b2894332dc1f7a97baa5a8c/zomabozejugulut.pdfIn PDF document text
    • https://digiconelectronics.com/media/sigixedonowim.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/b070f738c6533b7b83707ee3d6eb8fb9/20303881154.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa5a9843a1---kisakusijowokizeriviku.pdfIn PDF document text
    • http://shinex-auto.com/userfiles/file/40191761220.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=french+revolution+pdf+filePDF 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_off0000c688.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC688 10528 bytes
SHA-256: 85b8f77c11d2b0e9d1c03ada57b9bd4a40fd8c74ff8b4df6f0dfd01672bb5bb5
font_01_sfnt_off0000de58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE58 16448 bytes
SHA-256: 11a1e51d4eba936fd5506249cd97d3c77e8f8afc0a87d1a548ce264ddaff660c
font_02_sfnt_off000108a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108A7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1