Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7ad4683c1c591c5…

MALICIOUS

PDF

79.9 KB Created: 2021-10-07 00:56:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: cd178f136249087f9376f42bbebc91ff SHA-1: 6c1c4ed6ac3312a2ae2e37797121f0a57d0fdbb5 SHA-256: a7ad4683c1c591c5c2a408cc0de849c33f74381353d56f4c8932122b1f04e6ac
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The presence of external URI heuristics and link farm rules supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 http://pusancard.com/userData/board/file/32552273959.pdf In PDF document text
    • http://hferrynetworks.com/FileData/ckfinder/files/20210927_06CBA15D527C2038.pdfIn PDF document text
    • https://inmaabiladi.com/userfiles/files/4969130591.pdfIn PDF document text
    • https://gestionarival.com/userfiles/file/zonazodudaserirave.pdfIn PDF document text
    • http://intertribo.sk/files/12098524934.pdfIn PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/9kb5blbuu9butuade272jp9r0d/99069277478.pdfIn PDF document text
    • http://www.mattig-accounting.bg/fisiere/file/45761991513.pdfIn PDF document text
    • http://szwygs.com/upload/solitabipel.pdfIn PDF document text
    • https://cfaegaianascente.pt/portal/userfiles/files/29223549933.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/5194fa69c2654a6ff637ee4918528747/69528944165.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/sogitebaluk.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615ab9afa9020---67472849933.pdfIn PDF document text
    • https://dom4m.de/userfiles/files/nosanopasaruteb.pdfIn PDF document text
    • http://www.css-jp.com/upfile/files/2021/09/24/49805257112.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/72305092751.pdfIn PDF document text
    • https://granitabrasive.ro/editor_up/vodaxojiworanilosema.pdfIn PDF document text
    • https://tvmreza.tv/ckfinder/userfiles/files/bikozozanut.pdfIn PDF document text
    • https://yk-tech.com.tw/ckfinder/uploads/ckfiles/files/91526894888.pdfIn PDF document text
    • http://vtaky.sk/media/file/xufufebodo.pdfIn PDF document text
    • https://fjhi.org/userfiles/file/balifediruburifuvalegapo.pdfIn PDF document text
    • http://hebammenglueck.de/ckfinder/userfiles/files/divofubi.pdfIn PDF document text
    • https://adikkedua.com/contents/files/rodagudiwevun.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=flinn+chemtopic+labs+chemical+reactions+answersPDF 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_off0000d108.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD108 10844 bytes
SHA-256: f50ebbf490b9701331e986cde2010f6130015c1c46887bb6f99d89c360d6253a
font_01_sfnt_off0000e9a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9A2 18668 bytes
SHA-256: d7de8182e7f97aa90ef611f76f39e0c5b53a519188deb7988e14f05128a1137e
font_02_sfnt_off0001198c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1198C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1