Malicious PDF — malware analysis report

Static analysis result for SHA-256 753a8403ef1bdf0e…

MALICIOUS

PDF

68.6 KB Created: 2021-06-05 18:14:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 999d44604e8c704667c974b47f351b51 SHA-1: ccad2fd75a20410134d37d7070e844504cd24684 SHA-256: 753a8403ef1bdf0e14b37ac2b46e8bb9b99cbec33b9ef5c8cbde5fa5ad8e8861
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and disposable hosting, likely to redirect users to phishing or malware distribution sites. The presence of multiple external URIs and link farm heuristics strongly suggests a phishing or credential harvesting campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://infrive.ru/uplcv?utm_term=new+relationship+poems+quotes
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1609c8b91ecb0d---garujemu.pdf
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160a12d806815a---45791758112.pdf
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/g1jtu1ge9a5rov86u3eaa72stm/74280184643.pdf
    • http://photographybynami.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8c543a5a04---48103522384.pdf
    • http://washchienluoc.com/upload/file/belozukuzofaxefube.pdf
    • https://www.picmephotoboothhire.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607f35fd32e03---40762009329.pdf
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/8u73hp47nf4mt3rk004mdd7f7l/2616455552.pdf
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160908d3658347---lopope.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/9bffca1a7ab8ccadae1c10a4e33790cd/gerokomerab.pdf
    • http://bitite.lv/media/txt/122/file/71602574287.pdf
    • https://liniagdanskzydowo.pl/files/80589665273.pdf
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/rbujs4ibf685dhtknk2917p42v/buduzijek.pdf
    • https://martybermanassociates.com/wp-content/plugins/super-forms/uploads/php/files/0b8133f53c8027357091a290dc61fdd9/56220879316.pdf
    • http://all-pass.com/folder/editor/file/gunix.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d074.bin
c49e6836c4489c8932012add5466dbdcef2fa7b643562215f9b83544b87d531d		 pdf-font-stream PDF embedded font (sfnt) at offset 0xD074 5244 bytes
font_01_sfnt_off0000e233.bin
d7d7f3edf6e6fdfa68ccc0437951a2ad03bacab3bf3563802185a194e3cb7be9		 pdf-font-stream PDF embedded font (sfnt) at offset 0xE233 10432 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.