Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c631fa4a6520e08…

MALICIOUS

PDF

88.4 KB Created: 2021-08-29 19:44:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 8413ff1af72873930ed16c609bd76ed4 SHA-1: d2efaa6162f678915389f725115c8f332f81c76c SHA-256: 9c631fa4a6520e088f5bcb0d8c18d928123842bcadf3a7792ff5566413c72f2a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple compromised WordPress upload directories and disposable hosting sites, indicating a phishing or malware distribution attempt. ClamAV and ML classifiers strongly indicate maliciousness, and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirms the presence of a link farm designed for SEO manipulation. No scripts were extracted, but the embedded URLs are the primary indicators of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/04efd0c8cebc0bbbd0b9d605d300fa7c/97683329400.pdf In PDF document text
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/itft5alig23i34dtaldkh96tpb/terovigabiwetusu.pdfIn PDF document text
    • http://wadirumshootingstars.com/userfiles/file///rikezovat.pdfIn PDF document text
    • https://bozoklar.org/ckfinder/userfiles/files/6673952566.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/79538392634.pdfIn PDF document text
    • http://shopgraeagle.com/ckeditor/uploads/files/45806242990.pdfIn PDF document text
    • http://handlpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/mikowilo.pdfIn PDF document text
    • https://actorconseil.com/files/file/vaxaniziwopavulafikalapar.pdfIn PDF document text
    • http://tcihk.com/userfiles/17298847910.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160726edf46c11---27561889395.pdfIn PDF document text
    • http://www.makattakasinti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076375bb9ff1---mowebozekudowon.pdfIn PDF document text
    • https://hoakhanh.vn/uploads/image/files/jozipotipukulow.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160864ca90ff45---xigowomosujaxomafilulexet.pdfIn PDF document text
    • https://polymadeniyaglar.com/fckeditor/userfiles/file/74012430291.pdfIn PDF document text
    • http://autosklo.sk/pictures/file/76670123637.pdfIn PDF document text
    • http://spamsmsgiare.com/media/ftp/file/42088495810.pdfIn PDF document text
    • https://ceccarmaramures.ro/userfiles/file/rekivililepulajuj.pdfIn PDF document text
    • http://covinahigh1980.com/clients/1/14/147ee80f0cf2e08ca1b5067d21485a43/File/24354107905.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/wekanuvapomegufen.pdfIn PDF document text
    • http://kartywspomnien.pl/uploads/assets/file/70291590543.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607b04634848e---votasofuzebonururuwazinap.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/876ab59df3f4965ed6b99d021c94a8df/96338229658.pdfIn PDF document text
    • http://3colorjazz.com/fckeditor/userfiles/image/dojefavinivuduvu.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/b6e75432259076b2ae32c0d02642bf5f/womexezonux.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=software+pdf+to+word+converter+full+versionPDF 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_off0000f498.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF498 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010caa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CAA 17476 bytes
SHA-256: 914a6b33dee877a54c817203bf5f86e7e37cdd808f7f29fd3617645f1f1222f5
font_02_sfnt_off000139c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139C0 10940 bytes
SHA-256: e7097106f4eabcb65eeb5bc457e1df5679995e233a361ddb02c00d1fc30e4705