Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca38bf5e1d235470…

MALICIOUS

PDF

81.6 KB Created: 2021-09-03 09:33:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 0d355dadcf3d87dd87d1173630226ce6 SHA-1: 72c91829f86c0de6b2f3ae8d0a0d253429b3ac61 SHA-256: ca38bf5e1d235470e8fa4ab01e0b39954161aab03618654a4d767889ab0765c1
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 http://fly.no1-yes.com/userfiles/file/34706148485.pdf In PDF document text
    • http://ecilingirler.com/resimler/files/57826399312.pdfIn PDF document text
    • http://hytechplus.com/userfiles/file/gofimazojura.pdfIn PDF document text
    • http://cuatro-pr.org/sites/default/files/file/vebel.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/bisisapuxa.pdfIn PDF document text
    • http://devison-matras.com/upload/file/gutamexativ.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072652f502e4---rarogi.pdfIn PDF document text
    • http://tungalag.mn/userfiles/files/80453017607.pdfIn PDF document text
    • https://bohemiamaestro.com/webpagebuilder/ckfinder/userfiles/files/43178667243.pdfIn PDF document text
    • https://santevita-bg.com/ckfinder/userfiles/files/14074327143.pdfIn PDF document text
    • http://short-story.ru/upload/file/zukifis.pdfIn PDF document text
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/16092209e535a7---nolorojipuvepawubibifa.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/1606f72f2cb346---bojuduwerepinugiruwaf.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/b5d0edcab449c24d05da987ad530bff0/50615630402.pdfIn PDF document text
    • http://dexgerm.com/data/file/userfiles/files/gorizupuvupozugomava.pdfIn PDF document text
    • http://27derajat.com/assets/ckfinder/core/connector/php/uploads/files/duxufuw.pdfIn PDF document text
    • http://china-hold.com/UploadFile/file/20210522175545831.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1607b3107373cd---debino.pdfIn PDF document text
    • https://almondzwealth.com/administrator/imagetemp/file/zafavetavasotole.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1606ef787ef311---43804833646.pdfIn PDF document text
    • http://lyzebrno.cz/userfiles/file/vetewewatav.pdfIn PDF document text
    • http://kapsalonindex.nl/images/uploads/kipekilugiwalidovarosuzu.pdfIn PDF document text
    • https://postelezmasivu-praha.cz/ckfinder/userfiles/files/dapifenesogunikevupepu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=paraphrasing+sentences+worksheetsPDF 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_off0000d6be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6BE 10784 bytes
SHA-256: 3f84876313a9f33dca7efca2ca7a48981df3340bf5636f7b2f9b0d6c2f2362d3
font_01_sfnt_off0000ef9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF9E 18352 bytes
SHA-256: d385dd29bb22ceeea163c3ff7ec0d1d2f81eba99b47d3cc65586c140f48c839a
font_02_sfnt_off00011f63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F63 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1