Malicious PDF — malware analysis report

Static analysis result for SHA-256 beeb25a86b00a5fb…

MALICIOUS

PDF

77.8 KB Created: 2021-09-18 19:43:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 5e7274ed1290c43f38011ee2945e0bab SHA-1: b7640089f69c5ba2d00a784b7f56e2f5726e0097 SHA-256: beeb25a86b00a5fb54aa97e0c64ee007a56b88ea814d55258f39dfcedaeb44fb
96 Risk Score

Malware Insights

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

The PDF contains a large number of external URLs, many of which point to compromised WordPress sites hosting other PDF files. This suggests the document is part of a link farm designed to manipulate search engine results or distribute malicious content. The ML classifier strongly indicated maliciousness, supporting this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9829

Heuristics 5

  • 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://crewmak.ru/uplcv?utm_term=how+to+save+webpage+as+pdf+mac PDF link annotation
    • http://aytekinpolatel.com/image/files/79302533069.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/6153319cc186f40ed8e3951d6c96bab5/bofipanijukokok.pdfIn PDF document text
    • http://fantalife.nl/userfiles/file/23557614704.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613340f9463cf---bavawawula.pdfIn PDF document text
    • http://severstroysnab.ru/userfiles/file/xoduzuv.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/161429e7279a6a---pepavolupunamenesorumasap.pdfIn PDF document text
    • http://dd-eng.com/files/files/nuponamilatibedovizaf.pdfIn PDF document text
    • http://gk-eventus.ru/admin/ckfinder/userfiles/files/ruzit.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/26ab55d333b2d1a625f59403a0af2e1f/kisago.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/2f0b3d1071a1dd66273eb46035ec161d/37922164828.pdfIn PDF document text
    • https://rimi.sk/userfiles/file/34237803788.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/ajo4tauaehntuvjfp9ostud732/60341217454.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613285a56e1ad---winubosajaxakofibawugete.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ef9b71bfd1---31336579382.pdfIn PDF document text
    • https://tavio.ru/files/file/dopojaxuwel.pdfIn PDF document text
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/5a97dc8fc9a9f9e44a40c675d8784cae/nozilelujawaraveza.pdfIn PDF document text
    • https://reviewz.eu/app/webroot/files/userfiles/files/52547864837.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/neq64oqsljufs9u1e5i0sq4cps/21023432377.pdfIn PDF document text
    • https://agriplan-rs.com/dados/ckfinder/files/64346771154.pdfIn PDF document text
    • http://wo-kop.pl/userfiles/file/75496751275.pdfIn PDF document text
    • http://hongdacable.com/d/files/53073608323.pdfIn PDF document text
    • http://lecostationery.com/files/file/jisotupodusagipun.pdfIn PDF document text
    • http://www.kymkarajok.net/tiedostot/files/vixuxevizuje.pdfIn PDF document text
    • http://cck-brno.cz/ckfinder/userfiles/files/68052690769.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2c5b9bd71---julazubaliravake.pdfIn PDF document text
    • https://ibextrail.com/editor-images/29803280306.pdfIn 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://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_off0000cab8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAB8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e2ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2CA 17628 bytes
SHA-256: ab8d568043d64b2f2f418796d45ac1230dfb494971e3922ba062abac037d7c50
font_02_sfnt_off000110ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110EA 10904 bytes
SHA-256: 043f7e7e7b4cec562a89433dc3fa2702548c0283a0d087a9ec188b663b864f6d