Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a435b211948cfce…

MALICIOUS

PDF

74.8 KB Created: 2021-09-17 09:45:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3e0c2d4af1f3d2d7185b43fa24c5232f SHA-1: 9c3be8d99cc44b857f6929ca41698cdca3d29f4e SHA-256: 1a435b211948cfce2b964c8427956324f1f340bf8f82f9662b6cfa7f1de58df5
134 Risk Score

Malware Insights

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

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is likely used to execute malicious actions or redirect the user. The PDF also functions as a link farm, pointing to numerous external URLs, many of which are hosted on potentially disposable domains, suggesting an attempt to obscure the final malicious destination. The primary attack pattern involves exploiting the PDF format to deliver a payload or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/90278503622.pdf In PDF document text
    • https://drticket.ir/basefile/drtiketcom/files/41224877485.pdfIn PDF document text
    • http://webinaris.eu/ckfinder/userfiles/publics/files/rusuninezezamazugemo.pdfIn PDF document text
    • http://viettelhaiphong.me/data/dulieu/files/44436225886.pdfIn PDF document text
    • https://editora-arara-azul.com.br/site/admin/ckfinder/userfiles/files/6270236366.pdfIn PDF document text
    • https://printsolutions.ro/uploads/wysiwyg/files/wafag.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/cc2a53181d044db185c5b928e2b29941/78033608508.pdfIn PDF document text
    • https://gym-rectif.fr/ckfinder/userfiles/files/46231836984.pdfIn PDF document text
    • http://chinalabware.ru/d/files/42692646243.pdfIn PDF document text
    • http://koddous.com/userfiles/file/pokamiguvezapipidowem.pdfIn PDF document text
    • http://www.heatandgas.com/EditorImages/file/sififesazufuvokid.pdfIn PDF document text
    • http://rracc.com/file_media/file_image/file/36328033823.pdfIn PDF document text
    • http://carrasvilla.es/uploads/files/voduk.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/161422382a7895---sojakodizovujomiso.pdfIn PDF document text
    • http://dreiseengrundschule.de/files/powaponosor.pdfIn PDF document text
    • http://wabasnb.com/files/fckeditor/file/1519790672614398badc0e3.pdfIn PDF document text
    • http://whipitleather.com/userfiles/file/famepulovoxetumubotod.pdfIn PDF document text
    • https://ladulceseguros.ar/noticias/fckeditor/file/92232049441.pdfIn PDF document text
    • http://silver.jo/ckfinder/blanc/files/56974745052.pdfIn PDF document text
    • http://sayarbobinaj.com/file/18733382777.pdfIn PDF document text
    • http://www.taimaobi.com/admin/ckfinder/userfiles/files/nemefinosileje.pdfIn PDF document text
    • http://masonhn.com/d/files/kizofofi.pdfIn PDF document text
    • https://gullyracing.it/admin/ckfinder/userfiles/files/68742047209.pdfIn PDF document text
    • http://portofmiamitunnel.com/system/js/back/ckfinder/userfiles/files/82522403186.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=cast+to+tablet+from+pcPDF 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_off0000c39d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC39D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dbaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBAF 16388 bytes
SHA-256: 13841ec3e8f9284f1060dc8086271f73a166a2cd6a3d16d0defa7df79b2687ea
font_02_sfnt_off0001056f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1056F 10616 bytes
SHA-256: 03459cbafb7956c88e81ee02604373ea16624982f32575d67e666277036ece08