Malicious PDF — malware analysis report

Static analysis result for SHA-256 25309cfcb1780a75…

MALICIOUS

PDF

81.8 KB Created: 2021-09-02 11:48:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4c0395f2ee11f38c0bb28ee426baad5a SHA-1: 89d5b982cd1828359bc2126595f5e8602ee840e7 SHA-256: 25309cfcb1780a75b36201ae1a1f03ac2e7012cda4a5babcfce38fd64fd35daa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and ML classifiers indicated a high probability of maliciousness. Several heuristics point to the PDF acting as a link farm, directing users to potentially compromised websites, including one hosted on a compromised CMS upload storage. The embedded URLs suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • 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.
  • 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 http://capmar.eu/userfiles/file/60662512568.pdf In PDF document text
    • http://fitnessklub-impuls.pl/uploads/assets/file/pukewirominajejezozuju.pdfIn PDF document text
    • http://www.tobywells.org/media/fckdir/file/52761704939.pdfIn PDF document text
    • https://charterboatdeliverance.com/uploads/files/tivuso.pdfIn PDF document text
    • https://magatek.com/documents/file/1840828686.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086c4d8b0562---78681610260.pdfIn PDF document text
    • http://phaptangpgvn.net/app/webroot/upload/files/vikisuwobew.pdfIn PDF document text
    • http://modern-pro.ru/files/file/62573274205.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac34360c240---pavamotovewa.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160eca12868cfe---60914116392.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/fe06770a28b97890465ff59bb5d35b75/44218988111.pdfIn PDF document text
    • https://aathichudi.org/userfiles/file/62590235984.pdfIn PDF document text
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/jg34n91ji6pbknr6a11t7q0du5/puxofobe.pdfIn PDF document text
    • https://songhong-thudo.com/img/files/85641533309.pdfIn PDF document text
    • http://hillhouseclassof1961.com/clients/c/c9/c9b049383fb65e98d0a4dcab6c176392/File/dematabiwekoxatuwitat.pdfIn PDF document text
    • https://art4you.sk/editor_uploads/system/files/67415046129.pdfIn PDF document text
    • http://fgosvo.ru/files/files/6887945651.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160f68b0a16e47---xakit.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/762ib5gl8utcb2qgn19e4ue4k9/51450247224.pdfIn PDF document text
    • https://dukeofmarshall.com/ckfinder/userfiles/files/warabopig.pdfIn PDF document text
    • http://debeleven.net/UserFiles/File/2501466456.pdfIn PDF document text
    • http://criminisiepartners.it/userfiles/files/kugexamanokirofavowex.pdfIn PDF document text
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/e36dc6a4e2293901323d2175d2d1fb07/fefibaxumokumiwi.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/b0ca0e2d043046e5f8f0a3ea82526ada/vorelokuvidawuwan.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/ulkd170c8pcsiti9uja8vdful6/bagepujimatelotexozuri.pdfIn PDF document text
    • http://kvbm.org/pds/userfiles/files/9481103301.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=honda+civic+sport+2019+owners+manualPDF 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_off0000d914.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD914 17328 bytes
SHA-256: 59dea980bc3996ee544db1f57528db01bd9d880063390915dfde814549e86b09
font_01_sfnt_off000105de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105DE 11380 bytes
SHA-256: aceb37a49630fcf0931a4ff093965d93fe4a719666822e6a57d8ab894d08fcb0
font_02_sfnt_off000120ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120CE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1