Malicious PDF — malware analysis report

Static analysis result for SHA-256 b31b5dd3aee3ca98…

MALICIOUS

PDF

81.4 KB Created: 2021-09-05 13:57:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b068194bbbc1e9fc8285bfdc649d20bb SHA-1: 44a136788cea02c59d78345c2312822767325fda SHA-256: b31b5dd3aee3ca98240d39aaf75e97656b5eee45f512dd650760d8492e462391
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting, suggesting an attempt to distribute malicious content or phish users. The document's structure and embedded links indicate it is designed to lure users into clicking through to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://www.ksmt.edu.np/assets/ckfinder/userfiles/files/feguzegamipiga.pdf In PDF document text
    • http://chizclean.ru/files/fck/file/gexenobodogexulunupid.pdfIn PDF document text
    • https://hometeamcorp.com/images/usr/wuvusi.pdfIn PDF document text
    • https://thejinglelab.com/wp-content/plugins/super-forms/uploads/php/files/g7rd2ashposrmuurnqr57sfptb/48912463676.pdfIn PDF document text
    • http://afgventuregroup.com/cfiles/file/sebenamujinerikeru.pdfIn PDF document text
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ab82fd0511e1685b677552dc9e95dc6f/rozilovexotu.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607da570f2d48---88289694786.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086247142fb3---64645177459.pdfIn PDF document text
    • http://moiarchitekci.pl/pliki/file/mojanugitafofibexomaxifaw.pdfIn PDF document text
    • http://tomaszfilipczak.pl/userfiles/file/gizepikifogunovunad.pdfIn PDF document text
    • http://phuocthuan.vn/images/pic/file/rizivavurozogolipe.pdfIn PDF document text
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/8m3qk7eav2nmiq5t51507a6dfn/45225451913.pdfIn PDF document text
    • http://namlongprojects.com/images/uploads/files/vugolaxakakepakuxa.pdfIn PDF document text
    • https://31app.com/userfiles/file/13974205538.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/mojipukizawanewizuz.pdfIn PDF document text
    • http://mondoacquapiscine.com/userfiles/files/xujani.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/2bb8976199a3ffa280a76eecd7729b73/lamodowepobomo.pdfIn PDF document text
    • http://geoodwierty.pl/files/file/gomodow.pdfIn PDF document text
    • https://www.hinkler.com.au/application/third_party/ckfinder/userfiles/files/subimirojejatojawupo.pdfIn PDF document text
    • https://sharjahcements.com/images/bulk_images/files/nigol.pdfIn PDF document text
    • http://jngf.cn/files/file/pofupatigaramakunulafuput.pdfIn PDF document text
    • https://bestofbucerias.com/upload/file/bitali.pdfIn PDF document text
    • http://lurome7071.com/clients/e/ec/ec9741bbacd2a64db66b94b03f3cd24d/File/woramumotinuveperedovevas.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1608cb564577ff---kotaj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=hardware+and+software+pdf+in+tamilPDF 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_off0000d96a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD96A 17632 bytes
SHA-256: 8d3e76305c93f19964bc15b169a54108b0ab0b5987b9044dc48485d6fb71abf0
font_01_sfnt_off00010726.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10726 10736 bytes
SHA-256: d31c01066a2d839a24cb5cc0f7f6984df8e5fd3be31aee99f2d895e98d713de4
font_02_sfnt_off00011fcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FCB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1