Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3eab755c4bca772…

MALICIOUS

PDF

86.1 KB Created: 2021-06-14 06:23:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 0afc3105533189a11b35159f839843b9 SHA-1: feec2d48a60fff27bd3d4edd3772457b726a1378 SHA-256: a3eab755c4bca772f700504e6ed47cacab094d797f0b3a9808fe1f83d364cabc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the overall structure point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://infrive.ru/uplcv?utm_term=formal+language+in+toc PDF link annotation
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b63932896f0---fikowavorowenu.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/jpjs6a4glghiviq9v9od733q6i/41541645447.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/160bf38543f9e0---59644660162.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607a4345e15e9---nolaku.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076a3b4883d2---sasosoli.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/10891987800.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609180cf7f70a---semunonesiborasip.pdfIn PDF document text
    • http://eurekaelearning.com/upload/news/file/kolutubogotekinajope.pdfIn PDF document text
    • https://atamergranit.com/userfiles/file/mametegipezefulekubol.pdfIn PDF document text
    • http://avsa.org/sites/default/files/images/files/fobarisume.pdfIn PDF document text
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/1jesjlt47vlenjvvrqf02dvksb/gafagudijugozolire.pdfIn PDF document text
    • https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085a23c9e465---rifixivivigenuzeje.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607511d5e9b42---85371317081.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/1606d2632ef5c0---tujovesojufolewibemol.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609748f918e2e---redojasuw.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/a64068de9ed786ded2db3f40a7d9d1ec/23552033868.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000115de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115DE 4896 bytes
SHA-256: f658c170923c828d91c3e862a917674979bdae7f353e6fcc71ac0c12199cfe4a
font_01_sfnt_off00012674.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12674 10624 bytes
SHA-256: 7f71d753926b3db5a36ade082558fd7f315a45717c2aaa6600de94349a0af651