Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5a8820ef6052e85…

MALICIOUS

PDF

83.7 KB Created: 2021-07-01 15:12:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5b684581e523da755c16666afc10fe67 SHA-1: 585a3111a0cc0ab2389478a019ec937cbd14bb46 SHA-256: f5a8820ef6052e857a4dda0172ce7b5a7433f220deae4044ae48c98d3c43c3e0
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file that contains numerous links to external websites, many of which are hosted on compromised WordPress installations. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or distributing further malware. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics suggests an attempt to obscure the final destination or leverage SEO poisoning tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/pd4o6qc8na5d3bqduqhb9u8die/18501993112.pdf
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1608751b56dfb8---91253489134.pdf
    • https://renault-service.com/userfiles/lavotavikuxefifizo.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/v3r8cvpfg47hq1jub78kco3c11/ganidijajefigepotezafazo.pdf
    • http://grandinhr.eu/images/user/file/jizawusamatowoxunuboda.pdf
    • http://kuehllawpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lozojolupux.pdf
    • http://turagent007.ru/userfiles/file/26459340057.pdf
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/f85fd0c133793a31711880d894eaf784/12210528130.pdf
    • https://www.lightingsolutionsinc.net/wp-content/plugins/super-forms/uploads/php/files/148719f2d1c83299bba97da96efb1cc5/85143141311.pdf
    • http://bortran.com/upload/image/file/20210608020946.pdf
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c1b90957a0e---tarusodugit.pdf
    • http://www.puhito.hu/uploads/35759577814.pdf
    • http://stadtbild-intervention.de/Quansis/ckfinder/userfiles/files/29189633115.pdf
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c94962d1af8---runowagetanaxisavemalulu.pdf
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608bea8ea9369---39780546450.pdf
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d474a7ef8e---kozezakamogof.pdf
    • http://avstralianature.ru/ckfinder/userfiles/files/zoxodipelupixojefamuvudul.pdf
    • http://status-go.net/gfx/userfiles/files/23423073778.pdf
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a6c8a9a8706---1759820710.pdf
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/fs29nbbmnntob4v4rschg1q491/37235652797.pdf
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a10946c305---79694008743.pdf
    • http://ksnjl.com/userfiles/files/wujebogiduve.pdf
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/0b6e00d4081ec8f64defb96e395f0997/61811652925.pdf
    • http://naturalmis.com/userfiles/file/pepudupisexesoserutenirur.pdf
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160a650bacea9a---zojuraranoleliropalonamaz.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=900+sq+feet+to+yards
    • 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_off0000e49d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE49D 16792 bytes
font_01_sfnt_off0000fcaf.bin
9c39b0131be940d07719aefa9d5da18fdc27ee80114decbb95f4093d55a35395
pdf-font-stream PDF embedded font (sfnt) at offset 0xFCAF 17184 bytes
font_02_sfnt_off000129b5.bin
d0828fc144aa6ab43fbc63865f5502648c497898ff043b61a28dd5ab43cc0bf7
pdf-font-stream PDF embedded font (sfnt) at offset 0x129B5 10560 bytes