Malicious PDF — malware analysis report

Static analysis result for SHA-256 08541d8622408544…

MALICIOUS

PDF

82.7 KB Created: 2021-09-08 16:38:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 37c837622720d13d43d8d2e0f7446327 SHA-1: ae4ea4f03661115ab427b4af006629aedb488f19 SHA-256: 08541d8622408544b195f444fb60c7794058936bc71a74e82f0c04f0967b5395
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm. Several extracted URLs point to disposable hosting or compromised CMS uploads, suggesting an attempt to redirect users to malicious content. While no scripts were explicitly extracted, the nature of link farms often involves JavaScript to facilitate redirects or obfuscate the final destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://bistakalikotenetwork.com/userfiles/file/vawopujilamokaliwekexu.pdf In PDF document text
    • https://samsungvrvklima.com/upload/ckfinder/files/givajuvapumedusujozenezuj.pdfIn PDF document text
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612ebc77edbc9---20119680419.pdfIn PDF document text
    • https://skinrepublic.vn/webroot/img/files/wutajame.pdfIn PDF document text
    • http://rosesrealtyhomes.com/userfiles/files/87489077489.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/16131a81f18208---kefijelofepuxaj.pdfIn PDF document text
    • https://pre-www.bridge-college.com/uploaded/ckeditor/files/61620070.pdfIn PDF document text
    • http://ckrestaurantgroup.com/ckfinder/userfiles/files/bitixeki.pdfIn PDF document text
    • http://himalayakebab.com/shipinc/userfiles/files/93957359572.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/pq1deskpict3t0km9qusiu2fa2/fisopisejetijaperibiber.pdfIn PDF document text
    • http://jatyn.cn/upfiles/202109/file/1630988607.pdfIn PDF document text
    • https://yantrasearch.com/ckfinder/userfiles/files/dekujimoduji.pdfIn PDF document text
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/f46dbcc478709176ace413cb39334c73/newibadojojenesune.pdfIn PDF document text
    • https://aquaprosmart.com/userfiles/files/doregejalosobut.pdfIn PDF document text
    • http://greentreeprep.com/cote_dor_import/admin/ckfinder/userfiles/files/99709429878.pdfIn PDF document text
    • http://raegcafe.com/uploads/files/1083434015.pdfIn PDF document text
    • http://comlark.ru/userfiles/files/78614676726.pdfIn PDF document text
    • http://urjabatteries.in/userfiles/file/betuvedagepurejedesapu.pdfIn PDF document text
    • https://asoriofrio.org/ckfinder/userfiles/files/damelajogajurudere.pdfIn PDF document text
    • https://hainutedecopii.eu/ckfinder/userfiles/files/mokadujesedazaruk.pdfIn PDF document text
    • http://hig-hegmann.de/userfiles/file/8212209402.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=supreme+court+of+judicature+act+1925+pdfPDF 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_off0000da97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA97 11244 bytes
SHA-256: 595a82550c5a58a93f4dfcf7c2070c9f64fdcccf801b458a888239558b8479a0
font_01_sfnt_off0000f517.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF517 18284 bytes
SHA-256: 1428580035d18eed9038bdd1017f85a314ca08f88982c9828f3fd7c82923ba28
font_02_sfnt_off000124e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1