Malicious PDF — malware analysis report

Static analysis result for SHA-256 ea77fc1667463674…

MALICIOUS

PDF

71.2 KB Created: 2021-09-21 01:21:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 37d54b09720abd24da157df3f94d768b SHA-1: 9a61582964c6e43adff5282dff3357fbde11c75c SHA-256: ea77fc166746367427f9f06ebab91467005c8ec9f9b06fdc92a051f21931bd0f
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of techniques used to host malicious content or redirect to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://synerhu.ru/uplcv?utm_term=windows+10+iso+latest+version+free+download PDF link annotation
    • http://chinhsuasolieu.com/media/files/zagadobi.pdfIn PDF document text
    • http://theurbanbazzaar.com/userfiles/file/22352327063.pdfIn PDF document text
    • http://deltools.com/userfiles/file/52129368808.pdfIn PDF document text
    • http://bsp-plovdiv.org/ckfinder/userfiles/files/xovono.pdfIn PDF document text
    • https://cytairtool.com/test/userfiles/file/20210920_ae4bc.pdfIn PDF document text
    • https://weboonline.com/ckfinder/userfiles/files/murezevuluvovosofi.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/1613c674e43d46---xexizowifoj.pdfIn PDF document text
    • http://ptairsupply.com/userfiles/file/88537164263.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/161455cade21c2---89470002594.pdfIn PDF document text
    • http://alda.pl/ckfinder/userfiles/files/gigibejagole.pdfIn PDF document text
    • http://acevina.com/webroot/img/files/netijebenekelexelu.pdfIn PDF document text
    • http://suarezbeltran.com/aym_images/files/3722811652.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/161355f8187c9a---56200038592.pdfIn PDF document text
    • http://rockefellersgold.hu/editor_up/15682309886.pdfIn PDF document text
    • https://certifiedcollisionrepair.com/home/cert/public_html/ckfinder/userfiles/files/18105346364.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/nkbdrinp017ad3etn3othpsq8u/13580019618.pdfIn PDF document text
    • https://mikludava.lt/images/files/47389906567.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1614150776f211---82416555377.pdfIn PDF document text
    • http://studioingegneriavaragnolo.com/userfiles/files/jepivi.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/722c6f051905ee41e2a34607549f4bf4/23516537006.pdfIn PDF document text
    • http://fmmvn.net/userfiles/files/2883722489.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_off0000b5e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5E2 10668 bytes
SHA-256: bcef79d3a37b3f85f9586d660d2883ff90f232353a6f105c8520b13016f23905
font_01_sfnt_off0000ce8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE8D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e69f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE69F 15668 bytes
SHA-256: bc88fa9cfafe804fe1e28e3f6e088ace7dd1e3ba247f0c7eaac7164dd1b4ef8c