Malicious PDF — malware analysis report

Static analysis result for SHA-256 41ffa5e345ef64e5…

MALICIOUS

PDF

72.5 KB Created: 2021-09-17 20:15:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 6dee18fa27d593cadcb8068a9003934e SHA-1: 409d566e08d4c1ce253d9f74a924ced330926538 SHA-256: 41ffa5e345ef64e59e595add76ba2a286b351e92c43cedb7af2daf980a3cd1f4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm pointing to multiple compromised WordPress upload directories and disposable hosting sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of numerous unknown URLs and a link farm heuristic confirms the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://estoniapools.com/contents/files/suxatafufanewo.pdf In PDF document text
    • https://dalycity.com/wysiwygfiles/file/suvonaz.pdfIn PDF document text
    • https://brukspec.pl/upload/file/84809265464.pdfIn PDF document text
    • https://principesgs.com/userfiles/file/bumifu.pdfIn PDF document text
    • http://punaide.com/userfiles/files/81544970043.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/1613167a5c667b---dinegepabomeluzivev.pdfIn PDF document text
    • http://smartvoicecom.com/userfiles/giwadopa.pdfIn PDF document text
    • https://martabaktelor.com/contents/files/wimukebif.pdfIn PDF document text
    • https://lnpro.in/ckfinder/userfiles/files/53403692483.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613844bf41243---53382050895.pdfIn PDF document text
    • https://al-wesam.com/userfiles/files/20753424737.pdfIn PDF document text
    • https://vzglavniki.net/data/file/80609640683.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/aik29lk1sue6mbh4o3r81intg3/7507487899.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613b3dca59848---49492131212.pdfIn PDF document text
    • http://esangsok.com/upfile/files/21734993302.pdfIn PDF document text
    • http://dailymaytrogiang.com/userfiles/files/tonimelo.pdfIn PDF document text
    • http://chiaranannini.com/userfiles/files/78365813348.pdfIn PDF document text
    • http://antwerp-reefer-tournament.be/argt/files/10843969313.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142a7f1b1a5e---70897593774.pdfIn PDF document text
    • https://cyc-catering.pe/disac/userfiles/file/kofakam.pdfIn PDF document text
    • http://szpitalstrzelin.pl/userfiles/files/saguloda.pdfIn PDF document text
    • http://tks-forever.com/upload/2021/09/17/file/duvutolewabolajotufox.pdfIn PDF document text
    • https://sardavetri.it/userfiles/file/76664255484.pdfIn PDF document text
    • http://caycanh.vn/images/fck/file/62164059197.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=tool+hack+dragon+city+2020PDF 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_off0000bc1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC1A 15544 bytes
SHA-256: b8d3c2573f79ad846dfda298bd6b0ef3b88ecd17288e94371373c254752205ac
font_01_sfnt_off0000e38d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE38D 10760 bytes
SHA-256: 34bc28bd5988d93068aaf750147af0d016b5a174f94110d2976ab36a7797f240
font_02_sfnt_off0000fc1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC1E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1