Malicious PDF — malware analysis report

Static analysis result for SHA-256 ed5b1cc3b1d2d44a…

MALICIOUS

PDF

71.2 KB Created: 2021-10-06 15:08:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 9af16a108c5851603518ac9a99ae2a76 SHA-1: 1f9383fd4709b7bcf8e1492f4bb83a371d737fde SHA-256: ed5b1cc3b1d2d44acde9c85710bf29141539faa259d425bb29c23fab9e165ede
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a large number of external URIs, many pointing to compromised CMS upload directories, suggesting a link farm designed to distribute malware or lead to phishing pages. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

Heuristics 7

  • 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.
  • 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://coretry.ru/uplcv?utm_term=how+many+noughts+does+a+million+have PDF link annotation
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161500ddf9d7b3---rajefisonovujuso.pdfIn PDF document text
    • https://www.drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16137237cd41bb---16733499557.pdfIn PDF document text
    • http://diennuocdanang.com/uploads/image/files/segubor.pdfIn PDF document text
    • http://wonderful-foods.net/userfiles/file/7444399266.pdfIn PDF document text
    • https://samirkumarpaul.com/ckfinder/userfiles/files/vojakavezovinisisigadidot.pdfIn PDF document text
    • http://geofer.eu/userfiles/files/32836533596.pdfIn PDF document text
    • https://wemservice.com/ckfinder/userfiles/files/6131813432.pdfIn PDF document text
    • http://thingsantiquesla.com/userfiles/files/levulolunapaxofozoku.pdfIn PDF document text
    • http://jyotiacademicpress.org/uploads/file/30615864692.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16151f13812517---79431337822.pdfIn PDF document text
    • http://nextlab-semi.com/files/fckeditor/file/wonolowa.pdfIn PDF document text
    • https://locktactyuma.com/ckfinder/userfiles/files/larisuxeku.pdfIn PDF document text
    • https://www.mftelhas.com.br/adm/Editor/ckfinder/userfiles/files/5461101387.pdfIn PDF document text
    • http://www.pataniforum.com/admin/jquery/ckfinder/userfiles/files/37268190467.pdfIn PDF document text
    • http://xlith.com/userfiles/files/13268231768.pdfIn PDF document text
    • http://www.vikingmaterials.com/img/90800406599.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d2c0d045e9---23352039244.pdfIn PDF document text
    • https://birgatour.mn/js/ckfinder/userfiles/files/vumoxonifonixadipunuwo.pdfIn PDF document text
    • https://digitaluzaktanegitim.com/calisma2/files/uploads/99597299758.pdfIn PDF document text
    • http://arniuniversity.in/ci/userfiles/files/xarugevamasamuwifuwisupo.pdfIn PDF document text
    • https://vietnamairlinescorp.org/js/ckfinder/userfiles/files/13429423101.pdfIn PDF document text
    • http://finproekt-msk.ru/userfiles/file/pisulonawurate.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/59707dd77e440af3c625238b159afdee/gebozel.pdfIn PDF document text
    • https://lmetinternationalschool.in/ckeditor/ckfinder/userfiles/files/63637632411.pdfIn PDF document text
    • https://ajambary.com/userfiles/file/sivoremasefagofivi.pdfIn PDF document text
    • http://sportyou.fr/ckfinder/userfiles/files/62927014972.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_off0000b88a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB88A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d09c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD09C 14652 bytes
SHA-256: 21fbe42b377ca1bd72e63223b2bdbb10ea889b6e4b8cc816b8e6022043b940f9
font_02_sfnt_off0000f58d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF58D 10952 bytes
SHA-256: 1dae031b65a77c72cf9ee561c25347b31930317e35e83e290228068d31bee226