Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b1b819074db7105…

MALICIOUS

PDF

90.1 KB Created: 2021-07-05 22:23:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 2752825103bb7405338998a4301d61a5 SHA-1: 82439ddd5982a4cc0b9d49aa30bf5cd25f23e725 SHA-256: 5b1b819074db7105584217e3f59f942ec62c5030efecce169e3cad651607b757
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites hosting other PDFs. This behavior is indicative of a link farm designed to distribute malicious content or phish users. ClamAV detection and ML classification strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/a9f9e54786e30d0e1c5653eac6435018/xuximopebosuxibikadupu.pdf In PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16075f4db91b71---zaxokum.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0af6269d46---kadozewob.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///32766771433.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073d5d327505---jokokekeveno.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b14615742a9---60416014545.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160ad0f428d871---kuduf.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce16eba929a---jesefod.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160984228ebaff---rajulugopotupipotedolo.pdfIn PDF document text
    • http://longarmacademy.net/fckeditor/userfiles/file/61227189862.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/rdkmb47emi1ppfbhr1e7stljmi/42775180476.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/9034231150.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8745dbb88b---rixorixetukiresogim.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/68324908104.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16087fb4819d37---xunuzufegilatatade.pdfIn PDF document text
    • https://martensmgt.com/business_school/uploads/file/80859207160.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/deedc6226e735288b1d44a99fd2236ec/mulide.pdfIn PDF document text
    • http://seventyfirstclassof69.com/clients/60772/File/ximugitenarimutedoxala.pdfIn PDF document text
    • http://dj-venci.com/uploads/pages/files/bosixoze.pdfIn PDF document text
    • http://agriturismolionsfarm.it/userfiles/files/45797884666.pdfIn PDF document text
    • http://perchegouet.com/ckfinder/userfiles/files/titulomexekewesatalim.pdfIn PDF document text
    • http://buergerforum-tirol.at/file/jidofu.pdfIn PDF document text
    • https://scanclean.bg/upload/ckfinder/files/vanazuzolaxulebanozin.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=central+problems+of+an+economy+class+11+notes+pdfPDF 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_off0000fcef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCEF 16960 bytes
SHA-256: 4c6a2774c93d93f38bf431a41d502a74996ae096e6a283b2fd3637f9d153c555
font_01_sfnt_off00012957.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12957 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001416e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1416E 11024 bytes
SHA-256: dc4c7ed3e09d839c25e7c7801c143a2679fd18f6dda1901e63a9f1cd6c0661e6