Malicious PDF — malware analysis report

Static analysis result for SHA-256 f52f38866b153181…

MALICIOUS

PDF

73.4 KB Created: 2021-10-03 12:36:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 82f1cf7a7da51c0e8bb4033335db8441 SHA-1: c03fe5490b4e1aa9a5cba1fc02a29847ba40f180 SHA-256: f52f38866b1531815b3fdac9ecd0819adb3f56fc35f96af62f23d7bbb4833026
156 Risk Score

Malware Insights

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

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or are structured as link farms on disposable hosting, suggesting an attempt to lure users to malicious sites. The primary function appears to be directing users to external resources, likely for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9915

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://fundacionamigosdelmarcaribe.ong/ckfinder/userfiles/files/bozidimudapejerisududiga.pdf In PDF document text
    • http://sun-green.eu/ckfinder/userfiles/files/50823213542.pdfIn PDF document text
    • https://jurvamartin.com/userfiles/file/306798943.pdfIn PDF document text
    • http://kammatrans.com/userfiles/files/18511504756.pdfIn PDF document text
    • https://siangyun.com/upfiles/editor/files/834452442.pdfIn PDF document text
    • http://generaltubi.com/container/ckfiles/files/zuxinaxogajapozan.pdfIn PDF document text
    • http://colorsoftexas.com/ckfinder/userfiles/uploads/xilavabaxavuximapawilu.pdfIn PDF document text
    • http://villahetzwartepaard.nl/survey/userfiles/files/50671839392.pdfIn PDF document text
    • http://nwatchonline.info/userfiles/file/9243120413.pdfIn PDF document text
    • http://balalajka.nu/media/3387162376.pdfIn PDF document text
    • https://dichvumoinoi.com/ckfinder/userfiles/files/neluxidolimun.pdfIn PDF document text
    • https://securitydm.rs/slicice/file/21404638457.pdfIn PDF document text
    • http://www.ecrivains-consult.fr/easyonline/ckfinder/userfiles/files/59141483545.pdfIn PDF document text
    • https://www.aledrukujemy.pl/ckfinder/userfiles/files/rifufivonamoz.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/jife0j2o5k7mj9h2fsmhtuj6k8/89420143794.pdfIn PDF document text
    • http://gniortho.com/files/Upload/file/pogulo.pdfIn PDF document text
    • https://altaamir.ipixpms.com/Rapport/public/assets/ckfinder/userfiles/files/48550792476.pdfIn PDF document text
    • http://porpora.info/imagenes/imagenes_contenidos///sejumuvuleravilow.pdfIn PDF document text
    • http://ramenhajimetustin.com/uploads/files/19960666677.pdfIn PDF document text
    • https://natyabio.com/uploadfiles/62350436605.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161492a87ec809---zerosedexuxo.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/c507c17f7ef47c3f2b035a9c99473e5d/mafixu.pdfIn PDF document text
    • https://mashura.co/userfiles/files/nexozibasixakuxulutuxuz.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/amii894o11m0l76d10fjq9te63/34269065202.pdfIn PDF document text
    • http://3wsystems.com/shipinc/userfiles/files/57962617500.pdfIn PDF document text
    • http://www.luna1956.com/images/library/File/pobagasisufovoropotanuj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=addition+of+rootsPDF 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_off0000b9f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9F5 18700 bytes
SHA-256: 7ca3d4cf1786d00fb6b2513edabdb970b8b7874c9d04c4ff727ca69e29032d6e
font_01_sfnt_off0000e976.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE976 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001018c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1018C 9988 bytes
SHA-256: 30e1baf147f045078f2cd1a9727f802b2c233059d530fcf254934902af79fcc5