Malicious PDF — malware analysis report

Static analysis result for SHA-256 3825b922cbe6174f…

MALICIOUS

PDF

100.0 KB Created: 2021-07-01 21:09:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 9a09845d9466d02aff9b1c8d9e400923 SHA-1: 33f2ba177821f4588e1269cdc59fc68b2dfbbb9f SHA-256: 3825b922cbe6174f0657575dde8a1484fde4c2954ab0048239679a24b2734cbf
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggests this PDF is designed to redirect users to malicious sites or download further payloads. The specific heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a tactic to obscure malicious links within a large number of seemingly unrelated URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9678

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://synerhu.ru/uplcv?utm_term=soothing+sounds+to+help+me+sleep PDF link annotation
    • http://dinskayarealty.ru/media/file/nomajav.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/s2h33n7p3hkkuacsqlg24pv27g/zosotumalajazu.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/16079e98e896fe---wisukubaboveja.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/om90httm6ar72rgrmb38ar5vmh/83711697387.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/16077b69fb0849---pobeb.pdfIn PDF document text
    • http://suachuaspa.com/upload/images-content/files/6671014925.pdfIn PDF document text
    • http://ipmarketing.net/userfiles/file/xasatizikulinimemoli.pdfIn PDF document text
    • http://gold-carsales.com/js/upload/files/20632220344.pdfIn PDF document text
    • http://interiorconsignments.com/media/file/bevojeluzun.pdfIn PDF document text
    • https://angelsstaff.com/uploads/file/4813146259.pdfIn PDF document text
    • https://catequesisnavarra.org/guiarte_userfiles/files/viwibugubila.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/41ae66abfcf25b8c35d090ce0cacc528/92020022523.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/agbm9arq48n6s4q6domotjl4c6/givoja.pdfIn PDF document text
    • http://csc-0898.com/userfiles/file/20210613092350_9r1k1o.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/p7ona4eklg6r7qbsbretrceojb/lidewaxetazoxe.pdfIn PDF document text
    • http://speakingaboutnetworking.com/ckfinder/userfiles/files/xefofumo.pdfIn PDF document text
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/160846483414f7---dipogizomaz.pdfIn PDF document text
    • http://cloverdiamond.com/file/34825143606.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160817ea0666cb---nagibusezotemafisobevutuf.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606d23a90be83---razinexovumulo.pdfIn PDF document text
    • https://hasekei.jp/userfiles/file/84503839075.pdfIn PDF document text
    • http://domeinbeverdonk.be/assets/files/file/44096721747.pdfIn PDF document text
    • https://newtech-utm.pl/userfiles/file/luvesumifabebajesokojar.pdfIn PDF document text
    • https://xn--bren-mgenwil-gcbf.ch/sites/default/files/fck-uploads/file/fepowowazoluxusakajo.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1608039009fa9b---39885022916.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fcfa61cbde---sorazab.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010aea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AEA 17604 bytes
SHA-256: 87c290d73c291ce7fe9e66b07fa4305337ef33d5023be114d0070789d5c6c25f
font_01_sfnt_off0001392b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1392B 17840 bytes
SHA-256: 865d267d113315723de299c839a910ca94221b178218be457c92bfe31dad03af
font_02_sfnt_off000151c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x151C6 10752 bytes
SHA-256: 2251dd1bb514c83ba50708c3920df6bf2fb24d292d20eec1c724a152315c4e3b
font_03_sfnt_off00016a15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16A15 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1