Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb5b8e16479a389a…

MALICIOUS

PDF

71.5 KB Created: 2021-09-24 04:34:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 499948190a6f557d734aff495a5e27d5 SHA-1: 40baee59ce5648217534836464b699caafd9e8c0 SHA-256: fb5b8e16479a389a64db33252afb570337008e979f90d648e4eef8733d18f134
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO spam. Although no executable scripts were found, the structure and URL patterns are consistent with malicious document lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://crysiq.ru/uplcv?utm_term=most+unique+android+launchers PDF link annotation
    • http://ikcem.org/userfiles/file///49461190901.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613910e976fe5---34996833635.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/nofuw.pdfIn PDF document text
    • https://lolakarimova.uz/ckfinder/userfiles/files/miwefuri.pdfIn PDF document text
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/a5b97339b5f6834fdadd6a0aed39ce49/kosunokopegibowasur.pdfIn PDF document text
    • https://www.sterlingsez.com/ckfinder/userfiles/files/lugiwexavebowes.pdfIn PDF document text
    • http://seanbittinger.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sekisumotenabapakuluw.pdfIn PDF document text
    • http://generale-bureautique.fr/gdb/files/file/78819233451.pdfIn PDF document text
    • http://stoewebdesign.no/userfiles/file/fejebosiru.pdfIn PDF document text
    • https://fresh-cherries.com/ckfinder/userfiles/files/babopazarexabituz.pdfIn PDF document text
    • http://thienthaopc.com/upload/FCK/file/ritelowuneroluwe.pdfIn PDF document text
    • https://creativetalentnetwork.com/ckfinder/userfiles/files/1308528210.pdfIn PDF document text
    • https://fallahi-sch.com/userfiles/file/86851213216.pdfIn PDF document text
    • http://iberryhomemade.com/userfiles/files/43737618943.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/rsad2er7dn757b32pvm3shf442/nawixonuzavusofuk.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613be02b6274e---67105144035.pdfIn PDF document text
    • http://cissi.it/userfiles/files/20123242523.pdfIn PDF document text
    • http://club-integra.ru/userfiles/file/miburedivojolov.pdfIn PDF document text
    • https://newline-eg.com/userfiles/file/vuvavovutoxozufog.pdfIn PDF document text
    • https://ateliersmq.com/pevron/www/img/file/93278160574.pdfIn PDF document text
    • https://cardolf.ro/files/53156045075.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_off0000b79f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB79F 15820 bytes
SHA-256: 5435897a6349004a26e9f06fbbecf67495a7fe69fdb9d5a0feecbc1615349c11
font_01_sfnt_off0000e02a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE02A 10704 bytes
SHA-256: 15d8f0f02cd2fd77ec24afdf0732cff7f9036bf5b277b7cb89993f942dc45413
font_02_sfnt_off0000f87c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF87C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1