Malicious PDF — malware analysis report

Static analysis result for SHA-256 536f32f663f60c59…

MALICIOUS

PDF

72.0 KB Created: 2021-09-19 13:52:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 2b08157ba73b6c1fdbb7ac6892783b33 SHA-1: 2bff25c9c6ae1a3459e7b208239037ed02820a42 SHA-256: 536f32f663f60c59e251685dbd07e18bae70130af4cba4f9c5e3b2562e322404
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to various domains, many of which appear to be compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' confirms the nature of the document as a link farm designed to leverage search engine optimization on potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://coretry.ru/uplcv?utm_term=csr2+ios+glitch PDF link annotation
    • http://xdata.pl/app/webroot/img/ckf/files/biworozubevex.pdfIn PDF document text
    • https://myvideoclasses.com/ci/userfiles/files/85136554516.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/16143a2e571bab---12878958216.pdfIn PDF document text
    • http://myucmas.com/userfiles/file/52197336765.pdfIn PDF document text
    • https://sunsetlearningcenter.com/userfiles/file/77579278338.pdfIn PDF document text
    • https://nhatngudongkinh.phapluatvietnam.com/upload/ckupload/files/16506863993.pdfIn PDF document text
    • http://sahcarpets.com/userfiles/file/guwelomepi.pdfIn PDF document text
    • https://navoloki.mebel18.com/uploads/files/jasakaregodevifuvisuje.pdfIn PDF document text
    • https://sicurezzaips.it/uploads/file/93786446861.pdfIn PDF document text
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/f38ed208205af75911f298315629dc19/79989337300.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/93dni3ocvvklt8dnfed1pi1f6p/kitorovitafulefofarogugi.pdfIn PDF document text
    • https://malinaionescu.ro/userfiles/file/lufijajefekilur.pdfIn PDF document text
    • http://kalkulacka-hypo.cz/userfiles/files/80171292452.pdfIn PDF document text
    • http://ediliziaunoaventi.com/userfiles/files/ranetixawase.pdfIn PDF document text
    • https://livbiopharma.com/userfiles/file/86152413076.pdfIn PDF document text
    • http://sonhanint.com/uploadpic/sun/files/202109032036389353.pdfIn PDF document text
    • http://architectureanddesign.it/userfiles/files/27469328526.pdfIn PDF document text
    • http://aprt1day.ru/file/50247994087.pdfIn PDF document text
    • https://baigiangtoanhoc.com/upload/files/tukebizofafadibelorexe.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16146abdf13dd6---renabukozopabutojizukitir.pdfIn PDF document text
    • https://prestinireedcorp.com/userfiles/files/99871383385.pdfIn PDF document text
    • http://sintjorisparochie.nl/userfiles/file/bamivu.pdfIn 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://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_off0000b761.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB761 17260 bytes
SHA-256: f37f55189dd497afe1efdf52b1e9c30a504280ef537f654bc10d5fe5719f5738
font_01_sfnt_off0000e360.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE360 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fb77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB77 10260 bytes
SHA-256: ae90df538e9fb58d42b55e09d2f1dc1814845e01a2fc7ac026cd97ea28990825