Malicious PDF — malware analysis report

Static analysis result for SHA-256 55654e344d7fc7b0…

MALICIOUS

PDF

82.9 KB Created: 2021-09-17 21:51:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: ebf6643c90983ae513a91c604fb7997d SHA-1: f3bd6fc4ff3772bf89afded3cc0fd68142ded3c0 SHA-256: 55654e344d7fc7b0ba72db4c5b00cb2693f669008929a8d48fadd6f5b6432121
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or SEO poisoning campaign. No scripts were extracted, but the presence of numerous external links indicates an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://ugrctrani.it/userfiles/files/32066972736.pdf In PDF document text
    • https://medius.sk/userfiles/file/55236591654.pdfIn PDF document text
    • http://old.smartplus.pl/ckfinder/userfiles/files/xositakuzavozunodiza.pdfIn PDF document text
    • http://dongtienlamnghiep.com/upload/file/21946486883.pdfIn PDF document text
    • http://novosib-sport.ru/ckfinder/userfiles/files/50173958547.pdfIn PDF document text
    • http://fgsconsulta.com.br/ckfinder/uploads/userfiles/files/67330331511.pdfIn PDF document text
    • https://hefcom-hydraulics.com/ckfinder/userfiles/files/mizagejugatal.pdfIn PDF document text
    • http://vitacanes.com/uploads/files/56998469378.pdfIn PDF document text
    • http://yuhao-tech.com/userfiles/file/kobuxobova.pdfIn PDF document text
    • https://sahyadrisevasanstha.in/userfiles/file/46311198516.pdfIn PDF document text
    • http://weilandvloeren.nl/fckimages/10085374948.pdfIn PDF document text
    • http://giasuminhtam.com/Images_upload/files/vojalakuxokavebuvo.pdfIn PDF document text
    • http://technestudio.eu/userfiles/files/gakate.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613819e61e7da---11822604022.pdfIn PDF document text
    • https://www.grdr.org/paidel/ckfinder/userfiles/files/supuxomex.pdfIn PDF document text
    • http://33podarka.ru/pictures/files/70504167475.pdfIn PDF document text
    • http://www.kymkarajok.net/tiedostot/files/64127851387.pdfIn PDF document text
    • http://eta-aus.org/userfiles/file/20210901160639.pdfIn PDF document text
    • https://tamphuctriland.vn/upload/files/23973397845.pdfIn PDF document text
    • http://eko-uklid.com/files/file/24644712586.pdfIn PDF document text
    • http://bamila.vn/luutru/files/63211138594.pdfIn PDF document text
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/d3a72e81f6f05ec1d1c8e0b678ac6b48/31729608464.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161321a8d70009---sutajuwejez.pdfIn PDF document text
    • http://roycraft.ca/userfiles/file/72974448140.pdfIn PDF document text
    • http://bouwbedrijfansing.nl/userfiles/file/jukaketikotitapegusuxes.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=mx+player+eac3+codec+not+supportedPDF 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_off0000d80e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD80E 19856 bytes
SHA-256: b7c51e0e19bc2c61093bf6451334d57a8d4696be7221fca6d7c60ec248cf1ab8
font_01_sfnt_off00010c58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C58 10896 bytes
SHA-256: 40e4041d0bf55c1caa7f5eecafc2a8740cde27c493fd5104dccff7fd6cae413f
font_02_sfnt_off000125d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125D6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1