Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3f25dbe8e4171dc…

MALICIOUS

PDF

89.2 KB Created: 2021-06-26 03:04:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 4fd35a2d296c67ad7ca1efb926edb5f1 SHA-1: 8dde5b40739bf686c5ca415238a5cfb6e865202e SHA-256: b3f25dbe8e4171dc5fd0e0f53b2543580e6ba83e05376e09c74892b200cde6b0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document exhibits characteristics of a link farm, with numerous URLs pointing to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were directly extracted, the presence of embedded URLs and the nature of the heuristics suggest the document is designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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=national+cultural+heritage PDF link annotation
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a7cfecb298f---dipawovumivevinanorutor.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/160a8e8c7ec0f2---kitorowufox.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/5979f63eeda6e9cd85e6235bf4fac695/37564152794.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b592e8bcc18---68468395312.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/d56ac79fd119ebb130b7154f294fbd9b/58334280608.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/f8ff0765722b2bc41b2f4a17fcc6d8cf/pizegaze.pdfIn PDF document text
    • https://jetaime-shop.com/files/3732652156.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5ac31dc7a7---8317607711.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b1f1ae80e0d---4189900444.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eed979a8a0---7075150114.pdfIn PDF document text
    • https://brickbodysupplements.com/newerac2c/userfiles/file/17978760148.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/05fefd7bf7d17e6f896fa1f869d34484/71526580130.pdfIn PDF document text
    • https://carrieres-pierre.com/userfiles/file/tugipodazedamekakituw.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bc96ad51fdf---13270580005.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/iohborcv6mpdbntnfabbolk18m/19338581909.pdfIn PDF document text
    • https://gilbertems.com/videos/file/26720888402.pdfIn PDF document text
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/aqa73575aa191l9nma8t15flql/8412421968.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/160914aef57ea2---46914006716.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/d1fc24e9c36f3c8fb3d327c6f70966f5/raliruwukebolu.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/sboet6dl44n9t89j3li1defm70/fadufo.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091021f433ae---72934618860.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_off0000f812.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF812 17704 bytes
SHA-256: feae177422a53e2590bf1b0d0ac17fbf19bcd2543a7ba324659fa854f015d74e
font_01_sfnt_off00012689.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12689 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013ea0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13EA0 10416 bytes
SHA-256: 4a69b448f9fc4a4342b5e6e69285cf9dafb3b0c2c14e70741963d7379d1d5011