Malicious PDF — malware analysis report

Static analysis result for SHA-256 5db65598b1e505ef…

MALICIOUS

PDF

71.9 KB Created: 2021-10-01 19:03:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 5dddffc8d242144cb654df97b5a2b81a SHA-1: 2f26563451726e0a73277f5b544cc922b0976055 SHA-256: 5db65598b1e505efb3f9b0bb82e40e0955faa2b123aeb45dd5590cd419b22f3b
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or are part of a link farm hosted on disposable domains. The ML classifier strongly indicated maliciousness, and the presence of compromised hosting suggests an attempt to distribute or mask malicious content. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

Heuristics 5

  • 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://yuvasarkar.org/userfiles/file/galudagetumena.pdf In PDF document text
    • http://safiorida.dk/operatori/userfiles/file/jepixafutukexunaw.pdfIn PDF document text
    • https://www.prieur-equipement.com/ckfinder/userfiles/files/61719725400.pdfIn PDF document text
    • https://ssekolkata.com/ckfinder/userfiles/files/rameme.pdfIn PDF document text
    • http://sheilahancock.net/blogfck/file/neditumisonoxov.pdfIn PDF document text
    • https://lean-ds.com/upload/editor/file/biboxex.pdfIn PDF document text
    • https://edex.co/userfiles/files/mososuk.pdfIn PDF document text
    • http://xaydunganphubacninh.com/webroot/img/files/jewaputonisesoj.pdfIn PDF document text
    • https://myvideoclasses.com/ci/userfiles/files/zululiroxe.pdfIn PDF document text
    • https://goodmix-psc.com/userfiles/files/jafefoxe.pdfIn PDF document text
    • https://yk-tech.com.tw/ckfinder/uploads/ckfiles/files/forunopozani.pdfIn PDF document text
    • https://artedeeducar.com.br/ckfinder/userfiles/files/xivut.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/ihl539l01chvogeq3n0p12vr25/gokil.pdfIn PDF document text
    • http://volkshilfe-vlbg.at/images/content/files/51545353197.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/8g6qpol1vj9pkefbb0ls0tclm4/24052883758.pdfIn PDF document text
    • http://chengzechem.com/upload/files/nopus.pdfIn PDF document text
    • http://manuale.aziendasulweb.it/userfiles/files/498246507.pdfIn PDF document text
    • http://khodahoanglang.com/admin/webroot/upload/image/files/lopazuzasegebowad.pdfIn PDF document text
    • http://sieuthivatlieuhoanthien.com/upload/files/30364074079.pdfIn PDF document text
    • http://nationalherbo.com/userfiles/file/49065567192.pdfIn PDF document text
    • http://fruitvita.com/files/files/83554988941.pdfIn PDF document text
    • https://soccerauquebec.com/userfiles/file/nitanumat.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/noganor.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=how+to+change+icon+and+name+of+app+in+androidPDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b0ca37f16e---21017986666.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_off0000b443.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB443 10932 bytes
SHA-256: 25b5ff9cf129016f60cab5c862f58f54091bd6dfb458c6b8c7364613411e0821
font_01_sfnt_off0000cd2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD2C 16776 bytes
SHA-256: bf3b4f333d175c51c643736094ab85fe7deb4c8676e58097fb2b0881c09d31bd
font_02_sfnt_off0000f806.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF806 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1