Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc85b665b3198ffd…

MALICIOUS

PDF

82.6 KB Created: 2021-09-20 08:42:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 113a3d3e37115b070ed19685aa0b7fe5 SHA-1: 0f60f0c2e779f70d4103af31eba325169f6b1c8d SHA-256: bc85b665b3198ffdec8d66c096b3cdc636e1a05589dc6875ed7c664650df0ed0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to various domains, many of which appear to be disposable or compromised hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of creating link farms on such sites, often used for SEO manipulation or to host malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://garglob.ru/uplcv?utm_term=psiphon+handler+2021 PDF link annotation
    • http://solarissoft.com/img/userfiles/files/14572686986.pdfIn PDF document text
    • https://globalybm.com/ckfinder/userfiles/files/1630527971.pdfIn PDF document text
    • http://apartmany.cucoriedka.sk/data/files/12509836567.pdfIn PDF document text
    • http://studiopol.it/userfiles/files/19194487385.pdfIn PDF document text
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/28421093813.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16142231535543---4022200042.pdfIn PDF document text
    • http://eternaseguros.net/files/files/68439878320.pdfIn PDF document text
    • https://urologasdainys.lt/userfiles/file/duvidevawa.pdfIn PDF document text
    • http://czernavendeghaz.hu/admin1/file/guduki.pdfIn PDF document text
    • http://urparitet.ru/admin/ckfinder/userfiles/files/bizerijukaf.pdfIn PDF document text
    • http://footstepfloor.com/upfiles/files/kututebisexedukowi.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614028e76e5fb---doberigutekibik.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/16133da1118847---51936643780.pdfIn PDF document text
    • https://atputasbazes.lv/images/userfiles/files/gidurusivuf.pdfIn PDF document text
    • http://commandhousecreations.com/uploads/files/wekilotaf.pdfIn PDF document text
    • https://baglab.pl/galeria/file/nidegepasesixunamewer.pdfIn PDF document text
    • http://havefuntogether.com/image/upload/File/18031461048.pdfIn PDF document text
    • https://www.comperat-89.fr/ckfinder/userfiles/files/93141468759.pdfIn PDF document text
    • https://scalper.ir/data/files/file/34782469592.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/161331a6d4191d---maxerikomebovavufo.pdfIn PDF document text
    • http://ambvetsanprospero.eu/userfiles/files/lukibawowemubenikibufaj.pdfIn PDF document text
    • http://adbrf.com/files/fckeditor/file/197530477461330ecc02413.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC90 18288 bytes
SHA-256: cb3e69b10d2f6b3d5e5d94800655c0c029be57105d9590310f005670d83a5abc
font_01_sfnt_off00010c37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C37 10684 bytes
SHA-256: ab99e1686edd7ebb39cc62b3711bf40530a3812fa6722674da0574b3adcaae0b
font_02_sfnt_off000124a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1