Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b651aa606762417…

MALICIOUS

PDF

109.4 KB Created: 2021-09-21 10:33:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: d1e8b8cfa1687681ba1ff8ad5b1fd423 SHA-1: 5005e29e51739d52e3709c5a5f0ec8efd31fe3a7 SHA-256: 4b651aa606762417d048535db300127764b18d45cd9a0dbb55c6c36cd78ff15c
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://rabudiagnostic.com/userfiles/files/6010331867.pdf In PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1613f7de47f1e2---winiruzavovabijadogax.pdfIn PDF document text
    • http://mim2010.ru/userfiles/file/tejaditavatadekopaminuku.pdfIn PDF document text
    • https://aspirans.com/files/file/setazuwusoro.pdfIn PDF document text
    • http://mdknoodles.co/uploads/files/38917101520.pdfIn PDF document text
    • http://ratchee.com/ckfinder/userfiles/files/vojovekilopita.pdfIn PDF document text
    • http://iccjsc.vn/images/uploads/files/36397195598.pdfIn PDF document text
    • http://mweb.cz/images/file/60360604359.pdfIn PDF document text
    • http://perles-del-beya.com/userfiles/file/setizubumewazatagibegasoz.pdfIn PDF document text
    • http://acsalma.hu/userfiles/files/repopezotobixuxoson.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161354bff0607e---87961544319.pdfIn PDF document text
    • https://easternresources.net/ckfinder/userfiles/files/sekenoweku.pdfIn PDF document text
    • http://mintaialuminum.com/d/files/bonexikulukatazurunixom.pdfIn PDF document text
    • https://mariellatriolo.it/public/file/19805524312.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161396c1bad35c---mudepuxuxujomituzeg.pdfIn PDF document text
    • http://dreiseengrundschule.de/files/75693509858.pdfIn PDF document text
    • http://stavo-bazar.cz/userfiles/file/sexemewerevavadotezum.pdfIn PDF document text
    • http://studiotipaldo.com/userfiles/files/piguxejowes.pdfIn PDF document text
    • https://semut73.com/contents/files/85724896802.pdfIn PDF document text
    • https://adepotcustom.com/UploadFiles/file/20210909052702199.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/u2bqnscf1enmh1ehgsvhc5e5bb/49138466773.pdfIn PDF document text
    • https://trsoftyazilim.com/genelresimler/file/20029772365.pdfIn PDF document text
    • https://projetounificado.com/uploads/files/kopamojutekofiwizug.pdfIn PDF document text
    • https://www.bosingels.nl/ckfinder/userfiles/files/5407896177.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=base64+to+hexPDF 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_off00014065.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14065 10264 bytes
SHA-256: a6ac4943f1da7eedfb2eb5cca1bb800a75a8f36fff33d9e1a1acddb6106773bc
font_01_sfnt_off000157c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x157C6 21076 bytes
SHA-256: 4691f62a391d8b432a9b9fbcd0969547b059323447efd9eccc395e3c9374678f
font_02_sfnt_off00018fbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18FBC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1