Malicious PDF — malware analysis report

Static analysis result for SHA-256 18cd8181c9aacf8f…

MALICIOUS

PDF

80.6 KB Created: 2021-06-27 02:02:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 4066cfd396e9fab3f06c768eb205176a SHA-1: f869f23571fecfadcfaaaec766e7cb82e1196a4d SHA-256: 18cd8181c9aacf8ff3d4696b20341d25375ae06fe8430d5527ffee7494542542
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF document identified as malicious by ML classifiers and ClamAV. It contains a link farm pointing to multiple compromised WordPress sites, suggesting an attempt to distribute malicious content or phish users. While no scripts were directly extracted, the nature of the link farm and the presence of external URIs indicate a likely intent to redirect users to a malicious second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c30a02740c0---nosixitavusivadosovimuwiv.pdf In PDF document text
    • http://paroissedementon.fr/upload/files/bipez.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/c3a1oqv8pq0lvt9aubr0ne1plo/busavukirojofus.pdfIn PDF document text
    • http://ever0036.com/assets/uploads/ckedit/files/20210529205349.pdfIn PDF document text
    • http://www.odnpoznan.pl/fotki/file/file/15402779692.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/160ceab6b8c63b---ratitatixajopigulafeduw.pdfIn PDF document text
    • https://marljivo.hr/userfiles/file/vewukosedisudes.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160b5c4e4b2169---judirisexobofutabo.pdfIn PDF document text
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d66acceea85---gefonuvirodibewufejivin.pdfIn PDF document text
    • http://zbraneklapka.cz/ckfinder/userfiles/files/sebadikusopodalivofufax.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aca2ad4015b---69524238557.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/788e6964a78ff12eb8726737c69b28fb/nubirejoxopuxorabujudowo.pdfIn PDF document text
    • http://wksx.top/images/userfiles/file/katexuxoko.pdfIn PDF document text
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/u30mvlieimd6u4r3plblpkhu5b/tipitowufas.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/0c8a20cc85fd8aa65dfcb448f8e4979d/mupipi.pdfIn PDF document text
    • https://hfbee.tw/upload/ckfinder_temp/files/20210625094151.pdfIn PDF document text
    • http://arohitourandtravels.com/userfiles/file/maxotitoledag.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/5ffddd81cff635498a3378b6a597fbc9/deweguxegufigeposodidawi.pdfIn PDF document text
    • https://uaatc.com/userfiles/file/losukev.pdfIn PDF document text
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/2a90f5d8a805b57ac5bef0c2e9078c0c/95015831309.pdfIn PDF document text
    • https://medicentrumnz.eu/medicentrum/files/file/morenizijufutugapu.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/0544dc5d12ea9fb0a849ae6f02eb201e/xifok.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/uectk1h8qo8fqmm8ee43qkr7d0/tedelaruxuvesufedik.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/0df1c3982950f0830f57a2fe1898e985/gapenumod.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=itext+html+to+pdf+cssPDF link annotation
    • 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_off0000d85b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD85B 10480 bytes
SHA-256: 4fb8d2e38548601ef53d22eb58ab143de8c4317e936a5d332c9185200790e0e1
font_01_sfnt_off0000f035.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF035 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010847.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10847 17132 bytes
SHA-256: f9ee5472f4a0eac68cd00c8419250d754cb6caa23c16eba74f89dfc568d02500