Malicious PDF — malware analysis report

Static analysis result for SHA-256 838c57f603974465…

MALICIOUS

PDF

83.5 KB Created: 2021-09-08 09:19:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 107cc33381ba82c3806db593b094cd54 SHA-1: e8ccb6438d14aac96ab9148fe03ae621f6e4e7ba SHA-256: 838c57f603974465f0a2f4d7fcafeea6ef116631cd17e3cc14104fbf299db241
156 Risk Score

Malware Insights

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

This PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The document contains a link farm with numerous URLs pointing to PDF files hosted on compromised CMS uploads, suggesting an attempt to lure users to malicious content or phishing sites. The presence of multiple distinct hosts and the use of 'utm_term' parameters indicate a potential SEO poisoning or spamming campaign.

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://ehlibeytalimleri.com/resimler/files/nejetarepir.pdf In PDF document text
    • https://jordanadams.com/ckfinder/userfiles/files/kekidot.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606f65630619e---8205534496.pdfIn PDF document text
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/60a4168d1d1a189c39421a66c1a0a408/9063611101.pdfIn PDF document text
    • http://northmarking.com/userfiles/files/wuwafogafadejijumigufo.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3904170a0e---49044208047.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608c245facc1b---ranunetupizizubexudivomom.pdfIn PDF document text
    • http://cke.hk/userfiles/segitijidafufenulopojorub.pdfIn PDF document text
    • http://hpworld.hu/data/pic/Image/file/76285746267.pdfIn PDF document text
    • http://marklaliberte.com/fckupload/file/retir.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb7674b0254---tupapalojukejine.pdfIn PDF document text
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/a5f7olflg4ucajg13pq7i54lvt/wunofel.pdfIn PDF document text
    • https://empylean.com/wp-content/plugins/super-forms/uploads/php/files/bs3sq84eej3a0uoqdhh9ss1iio/17981430506.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609832db61488---winutodeladozitemev.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/0f1af401ef7bd98d9b92db5f27dd13e2/miparexilajapojuxetegirog.pdfIn PDF document text
    • http://dailyliving.nl/ckfinder/userfiles/files/mesifarujidusesonasuj.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/2e0fa44010c60023469b1c7b1ab0eaa5/35216340220.pdfIn PDF document text
    • https://ekselantechnology.solutions/ckfinder/userfiles/files/76921198942.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/16127210cc0b85---51599764610.pdfIn PDF document text
    • http://philippinesroadshow.com/wp-content/plugins/super-forms/uploads/php/files/ea1dfae8b48f841d5e8cda416c9101fb/paguramalu.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/27108928940.pdfIn PDF document text
    • https://procogs.com/FCKeditor/file/fitakoxerowi.pdfIn PDF document text
    • https://bosgo.mn/uploads/files/52175330133.pdfIn PDF document text
    • https://jucariicopilasi.ro/app/webroot/files/userfiles/files/vekozejizezotafil.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=simplifying+variable+expressions+worksheetPDF 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_off0000dc00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC00 18760 bytes
SHA-256: 5120d66b144a3f8ad793efb10684d3ddcf465c2e45ac5cde84409672db9e16c5
font_01_sfnt_off00010d52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D52 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012569.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12569 11480 bytes
SHA-256: 1b0f1488e5a128fafd6d152a95b4f061b7fa4febaceb85058df1b26c8df84a6c