Malicious PDF — malware analysis report

Static analysis result for SHA-256 c19f92c5778757c1…

MALICIOUS

PDF

87.0 KB Created: 2021-07-24 15:15:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: db6bdde72679adf12134477bdad2a9cf SHA-1: 188b7a888900e1f17f6ef5117ecc9fd4fe039b93 SHA-256: c19f92c5778757c1b2d78d8a26291c4b11b63d08a6b09ff7715838616345f19e
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other domains, which in turn host further PDF files. This suggests a multi-stage attack where the initial PDF serves to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16074476900c04---javegavenakekudo.pdf In PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aaad4432ee5---sewovipep.pdfIn PDF document text
    • http://ladyqueen.it/userfiles/files/sonakaxa.pdfIn PDF document text
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/c4e0f82fe9ad9498f3748a4312e589f9/tufaxajuro.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160f551c793690---50449590561.pdfIn PDF document text
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/5rsu7aorimnqjjr3modrm5n1h6/98940410639.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/57401074332.pdfIn PDF document text
    • http://oresteruggiero.com/userfiles/files/wozasotagedubunuzavi.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/e8c3838435d3fc23b89e3734b61095fd/62698072019.pdfIn PDF document text
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bb1686bd42---58532443736.pdfIn PDF document text
    • http://universalthailand.com/images/uploads/ckfinder/files/mekorapur.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b4035b27328---zavebof.pdfIn PDF document text
    • http://aircond.md/upload_fck/file/93382248148.pdfIn PDF document text
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/a4quo5m59ii7ohbufhriuv3831/sezifokowitakafupenal.pdfIn PDF document text
    • https://beatmuellerfoto.ch/userfiles/files/xidusuv.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/16078b73f96668---31076453254.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609a71368916d---deserebitazusexema.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16078e2929f667---pemoforixorarerewemuxuze.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/91128785aeb02c2c0a65d2e4e2b96ace/23750270893.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/97733637021.pdfIn PDF document text
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/16073c2eea4456---wuzovakiwi.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f261fde836---nufojavazexaretoxaropen.pdfIn PDF document text
    • http://partnerplus30.ru/images/fornews/files/50273881218.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b630cd7c382---vegepenidatuf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=present+simple+and+present+continuous+activities+eslPDF 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_off0000f131.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF131 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010943.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10943 16360 bytes
SHA-256: a780dd2e5cce66b01c90d5d19543dab5399b50eb117dc60a09993670b5802482
font_02_sfnt_off000133e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133E7 10844 bytes
SHA-256: 120ad4cb37ff205855835b834a2d759f71c8272bc7f33094a864be0cefe1c903