Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4735144d547f959…

MALICIOUS

PDF

87.4 KB Created: 2021-09-06 10:11:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 6c2e84f9b27474940185ca32bcc396c2 SHA-1: 4741fe217a6db26aa6a98ce29af36b13257e6044 SHA-256: d4735144d547f959e3d2127e0fd4aab5242c746d1354364bfa8ac03625ac32c2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external URIs and link farm heuristics, indicating its primary purpose is to redirect users to other sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or SEO spam. The file's structure and embedded URLs point towards a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://cructi.ru/uplcv?utm_term=root+words+list+pdf PDF link annotation
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/6vboqdcr6tlfep0gkkkavtd6oa/93890004595.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/5b3400cbd6d7f58e480e3d88c0efd081/dejemad.pdfIn PDF document text
    • https://aynadakikemalizm.com/resimler/files/6497650446.pdfIn PDF document text
    • http://teplospectr.ru/images/files/53589817470.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/e68faa3d211c75ec0b61c32db7248f5f/23478571582.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ff8a76c710---97935050887.pdfIn PDF document text
    • https://pcetravel.com/files/file/pigijopupifazofa.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/160bdd1aa4670b---pufaviposusaker.pdfIn PDF document text
    • http://esipro.lu/userfiles/file/sigebozisur.pdfIn PDF document text
    • http://xn--80aagkbrca3apkgkee0a1bi.xn--p1ai/ckfinder/userfiles/files/kavedutokewepofipusixig.pdfIn PDF document text
    • http://asia-test.informacittadino.net/media/files/ketubumawodegomuvufid.pdfIn PDF document text
    • http://portableandcool.com/files/files/8607097561.pdfIn PDF document text
    • https://plentis.eu/ckfinder/userfiles/files/nudofuzovegefuraxosupepo.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077588ae284c---92802888776.pdfIn PDF document text
    • http://pogologistics.com/ckfinder/userfiles/files/vomipoze.pdfIn PDF document text
    • https://fedico.ca/upload/editor/file/fezaniparifibasulujimat.pdfIn PDF document text
    • https://dacinsara.ro/fckfiles/file/povakurabad.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610db2a5414a2---ruwolapusimutibojalomap.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/375ddbd2ee3f2a64d7ce8d81b69ca8ec/92052341018.pdfIn PDF document text
    • http://agro-vostok.ru/userfiles/file/ruwaxeporazefuzuli.pdfIn PDF document text
    • https://www.thc.gda.pl/ckfinder/userfiles/files/77995575692.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_off0000ed5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED5D 19924 bytes
SHA-256: fb24426567f58ad5f2dac79ad9a0a41fa48da048efa9cb4418d2747f0f19d8e8
font_01_sfnt_off00012166.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12166 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001397d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1397D 10224 bytes
SHA-256: f274a3d92dee15ec6e13136dfe04f05656356ee6b6cabae73058117825338cdb