Malicious PDF — malware analysis report

Static analysis result for SHA-256 51ac6d3e631ff745…

MALICIOUS

PDF

83.3 KB Created: 2021-09-19 04:29:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9c90ee1cd6dadecde0187470f16dee8e SHA-1: 582952f8bf868018bc95f18c94207c860be85aaf SHA-256: 51ac6d3e631ff7451c31e8de9eed10cc30fbdec4cbe6268188605caf3f6b68e8
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to domains that appear to be part of a link farm or hosted on compromised infrastructure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or directing users to malicious content. The presence of numerous external links suggests an attempt to lure users to external sites for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://garglob.ru/uplcv?utm_term=what+does+the+color+purple+make+you+feel
    • http://h-p-n.fr/catalogue_dynamique/file/fadinuxadopit.pdf
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/55a580713c8a809507c5e2d6ef377b4e/65183308727.pdf
    • https://dimensionshoppe.com/alpha/ckfinder/userfiles/files/vepenamar.pdf
    • http://jsjxh.org/filespath/files/20210914102620.pdf
    • https://produktybhp.pl/pliki_user/File/kasaf.pdf
    • https://rockeit.com/userfiles/file/33770286306.pdf
    • http://vitalchurchesinstitute.com/files/file/puketozuwabu.pdf
    • http://altadirezione-consulting.it/userfiles/files/begel.pdf
    • http://shopcloud.cloud/ckfinder/userfiles/files/natepegimotidipixamok.pdf
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16142571ca609a---xevuviso.pdf
    • https://www.indoorclub-informa.com/boletines/img/file/vasid.pdf
    • http://ji-tien.com/userfiles/file/taxojapuro.pdf
    • https://www.utn.ac.cr/sites/default/files/files/kawajudanewifili.pdf
    • http://silver1979.com/upload/file/sunarewej.pdf
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613530ebee196---vagagedirisegitojovas.pdf
    • https://optimuselearningschool.com/learning/site/images/uploadfiles/temevigapurefedutirop.pdf
    • https://www.moxiclear.com.au/application/third_party/ckfinder/userfiles/files/19379567904.pdf
    • http://lafenicealcamo.it/userfiles/files/sufasufixitexuxirasawa.pdf
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/73666286832f41fd727af4a79ab69b8a/14640521157.pdf
    • http://print-resource.co.uk/ckfinder/userfiles/files/36884996755.pdf
    • https://kiaavcilar.com/upload/ckfinder/files/27962541513.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df5e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF5E 16792 bytes
font_01_sfnt_off0000f770.bin
2223a717567ad004bcd688cdbd6ea4340ed180d0db471eae8774edc309ff4df0
pdf-font-stream PDF embedded font (sfnt) at offset 0xF770 17940 bytes
font_02_sfnt_off0001257a.bin
623f674286d25be8e016ac288887090377b6c3e69fa523410598c588c2cd74ef
pdf-font-stream PDF embedded font (sfnt) at offset 0x1257A 10988 bytes