Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cb2b2fdc5c14275…

MALICIOUS

PDF

78.6 KB Created: 2021-09-22 09:14:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 00cf9bbc82c2696282aa3da27e847e4c SHA-1: d7d98dac145126ab2cec297ea26223bb693c5132 SHA-256: 4cb2b2fdc5c142759b930076a6b27f4a8a308a4e0c9efb51b5e29f65673a0d5d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads. The document body is heavily obfuscated and unreadable, suggesting it's designed to obscure its malicious intent rather than convey information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 http://open.ua/uploads/ckeditor/files/11235043078.pdf In PDF document text
    • https://ccskin.com/geektic/files/gozagun.pdfIn PDF document text
    • http://probeg2000.ru/files/userfiles/files/walidewifopefisoladimite.pdfIn PDF document text
    • https://lazdynumokykla.lt/userfiles/file/jenozogegisujodu.pdfIn PDF document text
    • http://beverly.kopanramen.com/uploads/files/futofote.pdfIn PDF document text
    • http://cutskytools.com/d/files/81129797039.pdfIn PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/df63f75c6caa33316f4902c6962f908f/74028003474.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/ulh49fequsvsa58aio9h32r0f1/2177836247.pdfIn PDF document text
    • http://alessandrobelleseveterinario.eu/userfiles/files/52805250270.pdfIn PDF document text
    • http://cs-web-design.de/ablage/userfiles/files/kodireraguzorel.pdfIn PDF document text
    • https://ceccarmaramures.ro/userfiles/file/30764554420.pdfIn PDF document text
    • https://www.adoz.cz/ckfinder/userfiles/files/22199110295.pdfIn PDF document text
    • https://adeptos.clevercloud.pt/images/items/files/13471587016.pdfIn PDF document text
    • http://salt17.com/userfiles/files/vapiwoto.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613170c140ef6---bumaziralafezunakum.pdfIn PDF document text
    • http://thoitranglani.com/upload/files/29503189869.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/2340968842d639be77927a7614023d21/55709776158.pdfIn PDF document text
    • http://sahcarpets.com/userfiles/file/4466853693.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161422eaf4ea05---kuxolawaxelirawagoruf.pdfIn PDF document text
    • http://ongxoanhdpe.vn/upload/files/33198225419.pdfIn PDF document text
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/eh9a5538n8s8222vo4a4u1qq03/sitoni.pdfIn PDF document text
    • http://www.poliklinika-hb.cz/userfiles/file/46149811134.pdfIn PDF document text
    • http://ingmontagna.com/userfiles/files/59127834105.pdfIn PDF document text
    • http://salonorganica.ru/upload/files/40904732082.pdfIn PDF document text
    • http://starwindows.ie/ckfinder/userfiles/files/27448151652.pdfIn PDF document text
    • http://seatraderhk.com/userfiles/mupibajeg.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=report+description+examplePDF 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_off0000cf67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF67 10820 bytes
SHA-256: 8dcd87d6ab18a6485da4450c798e367748f0d2472b47fc938abcb8f25902ec5c
font_01_sfnt_off0000e853.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE853 17140 bytes
SHA-256: bc428c5c897f227becd9a99647fec1c3db67802b7bd0fe9fdd6afabcb429ef51
font_02_sfnt_off0001145d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1145D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1