Malicious PDF — malware analysis report

Static analysis result for SHA-256 13e6cbbe22f31156…

MALICIOUS

PDF

79.4 KB Created: 2021-09-13 14:52:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: de2c843707da2b3e28e2c4d51c0c8abc SHA-1: 4b2b3deb43c7e4d9133e298be72e6dfb4dfc3d30 SHA-256: 13e6cbbe22f31156dc63670477e02e5d8c3cbb8a33186a5b1e35361014f42ca8
156 Risk Score

Malware Insights

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

The PDF contains numerous links to unknown domains, with several heuristics indicating it functions as a link farm hosted on potentially compromised or disposable infrastructure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or to serve as a dropper for further malicious content. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://myphamlulanjina.com/upload/files/gidegoxebolagodudoreno.pdf In PDF document text
    • http://arsvet.ru/img/upload/tuwafixumugogi.pdfIn PDF document text
    • http://teifsepahan.com/files/file/19309613059.pdfIn PDF document text
    • https://marblo.com/app/webroot/img/files/98446710114.pdfIn PDF document text
    • http://gazdalkodjokosan.hu/img/userfiles/file/47274482571.pdfIn PDF document text
    • https://contabil-fiscal.ro/mm/file/gujevet.pdfIn PDF document text
    • https://olterus.org/contents/files/zotef.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16132bc688ea2d---61293052318.pdfIn PDF document text
    • http://longarmquiltingacadamy.com/fckeditor/userfiles/file/kanaxolotobobo.pdfIn PDF document text
    • https://sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/161323a8fabf5d---kivanibet.pdfIn PDF document text
    • http://hertzlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dixufokebowepagez.pdfIn PDF document text
    • https://faktxeber.com/resimler/files/68843912176.pdfIn PDF document text
    • http://hyunshin.net/userfiles/file/76709573937.pdfIn PDF document text
    • http://www.texaco.bargiel.com.pl/ckfinder/userfiles/files/zexajuvikefixati.pdfIn PDF document text
    • http://maihome.hu/admin1/file/taxibuvunelosenevazirad.pdfIn PDF document text
    • https://renewone.de/files/juxelesisofep.pdfIn PDF document text
    • http://mrcubezpieczenia.pl/app/webroot/media/files/61758237235.pdfIn PDF document text
    • http://yanarfabrics.com/firma/files/92669902519.pdfIn PDF document text
    • http://kcpsystem.com/userData/board/file/51361470218.pdfIn PDF document text
    • http://flyingfish-stay.com/userfiles/file/fasiladez.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/dqj8kho67ttvd4j5bpfibdhkhk/52471611474.pdfIn PDF document text
    • https://liftsystems.ro/LiftFiles/file/69726106629.pdfIn PDF document text
    • https://nepalonlineexam.tisaracademy.com/userfiles/files/42486361780.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=antutu+benchmark+full+apkPDF 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_off0000cc27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC27 10676 bytes
SHA-256: 9d488bf8a2c963156e4f92842cf7dc89824bb6e47fcd8a2e2a1d358a40e5379a
font_01_sfnt_off0000e43e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE43E 19872 bytes
SHA-256: 9530fb67e1d5d79f18bbdf8c9541b7f4485ffc89196d429ec3e6b29bde6b304d
font_02_sfnt_off00011855.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11855 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1