Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4e7821886bede84…

MALICIOUS

PDF

72.9 KB Created: 2021-07-03 10:54:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: f8cebff5e446b49afa662cb4932de201 SHA-1: 882d33dbae5f67368b85a345b9dbdc0dbb9d95df SHA-256: c4e7821886bede84116c583b8dadc6b8c995385068957172be6d0c4121d6dded
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting it functions as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of external URIs and link farm heuristics confirms the document's role in directing users to potentially harmful external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608af3379d4de---renunakuzal.pdf In PDF document text
    • http://windmill-bv.com/userfiles/files/rejujodinexipedek.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c71ead1eaf0---94059767650.pdfIn PDF document text
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b089db25d8d---zilaxemozov.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608d47bd5f723---golik.pdfIn PDF document text
    • https://arvikabc.com/images/uploadedimages/file/69362390019.pdfIn PDF document text
    • https://jodhpurtravels.com/nbloom/fckuploads/file/7330614736.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160df8281c453a---53754348584.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/4fa663d7f57a5aea2968358703607708/kabajizijefojibifuroroj.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c79a3929c5---fixasovomuzinosune.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c7baac6c174---38008630860.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606caf8203ce2---bojewezajivapex.pdfIn PDF document text
    • http://nousgarage.com/userfiles/file/99298163338.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/d98fa64c57bcaf56d5e11b233331367a/23990130462.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/16087550bed346---90953595799.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160b51274891b2---92361653241.pdfIn PDF document text
    • http://footstepfloor.com/upfiles/files/79023886115.pdfIn PDF document text
    • http://grandp.ru/userfiles/file/pejoro.pdfIn PDF document text
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/39et28rpahs4b6t6re72ut6oq4/38965049564.pdfIn PDF document text
    • http://www.festivalmarrakech.info/wp-content/plugins/formcraft/file-upload/server/content/files/1609ce3aaaf4f9---niwunijupidomolileb.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/d3n8vdbd6vfsmlmg6ku13ucqso/2115727436.pdfIn PDF document text
    • http://clubmaniacr.com/campannas/file/nebisuwazazuxifedo.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd14999ab88---fadusewebosonipijat.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=c%23+basic+interview+questions+and+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_off0000c154.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC154 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d96a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD96A 9104 bytes
SHA-256: fe4a9ad32d6d12da45ce8861a1e6e511df5579fd33367a5c4d1c9e774d301804
font_02_sfnt_off0000ec37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC37 16436 bytes
SHA-256: b24668138c6df4838ba110c4a3608676955da2fe50145a2f32b0a1d7e267e7db