Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c4b623959d87e11…

MALICIOUS

PDF

80.7 KB Created: 2021-07-07 20:52:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 91c23ce286f041c23ce9ee9cc6f3cf5b SHA-1: 9c43be768f3f8cab1ee10141e786d31517ecaaca SHA-256: 6c4b623959d87e1162f12573368d03e39ea704142f14278c6ebd91b31e123390
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs pointing to compromised WordPress sites, suggesting a link farm designed to redirect users. The presence of external URI heuristics and the compromised CMS upload link farm indicate an attempt to leverage these sites for malicious purposes, likely phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://coretry.ru/uplcv?utm_term=if+i+lost+my+drivers+license+can+i+drive
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607f5e030d31f---97542625286.pdf
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/2d044bd1276a22a6ad8549c02b95ee2b/26016557619.pdf
    • https://autoteam.in/ckfinder/userfiles/files/mobozozemerilidupin.pdf
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f8e6482cf0---vowijosijedan.pdf
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e18e17dd9f---nabuzi.pdf
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/n35jlssepj70bs8hfsvqfa9jt0/73001066920.pdf
    • http://www.socalgreatwhite.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cdc6437163---38240456979.pdf
    • https://vandolderskb.com/images/usr/visobuva.pdf
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098b862d93ca---mopav.pdf
    • http://belgium-ex.com/images/blog//file/16550812438.pdf
    • http://vodnik48.ru/content/file/disanogix.pdf
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d1d2aaad53---25205586233.pdf
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16094132a9e287---38100675192.pdf
    • https://siroyensao.com/upload/files/kigasafunid.pdf
    • http://xinyaoqiye.com/upload_fck/file/2021-6-4/20210604172215136197.pdf
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afa82aedc82---71082577214.pdf
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160858253eed02---zedifubo.pdf
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/ohst1a1sp6iahrmv9u6h3gns4m/rabolajosonapokezuv.pdf
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/3601883d49d59c70cccf29156c022382/71329993958.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/1p9dcbi9rfeplqc1o60lt9ceo8/15705583039.pdf
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/zemuvifabewatupe.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094c92791e61---59967781037.pdf
    • https://maplesservice.com/wp-content/plugins/super-forms/uploads/php/files/799a7e9e8da840451be919d877f4d44c/gapozalewiwag.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db6d.bin
e238a9092f71c6a583d8d50a3ba70d40ba346344cd9d7d0ed0aa839e19346d9d
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB6D 10768 bytes
font_01_sfnt_off0000f436.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF436 16792 bytes
font_02_sfnt_off00010c48.bin
2e448faa722a3b3a1415672eee2d1bf69c751640ac0e95183952fdf793525237
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C48 15984 bytes