Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1e8cd88cfcd5be3…

MALICIOUS

PDF

89.6 KB Created: 2021-08-13 00:51:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e9743ac0e059941480a53bbf47f5a5c1 SHA-1: 41be783832351bfcd79020372b4f9f132328f92e SHA-256: b1e8cd88cfcd5be3f7352f3d68070f547fb47611863bc7cf07afcf0c5ff346dc
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to compromised WordPress sites, suggesting an attempt to lure users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://krisoc.ru/uplcv?utm_term=7+hermetic+principles+wikipedia
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160f50bb5bda63---83720615777.pdf
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092b80717300---90680527349.pdf
    • http://sea-cruise.ru/ckfinder/userfiles/files/86589204217.pdf
    • https://guijek.com/userfiles/file/jutatemexito.pdf
    • http://pphu-joanna.pl/fckpliki/file/sogitafabadonabodilal.pdf
    • http://cayxaotamphan.net/userfiles/image/file/nonukazuwe.pdf
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/c2f9eeaf02e27d94f3ce001597792a27/xodidew.pdf
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d026835ca9---kikegeribelukisesekikut.pdf
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/j62s19jik0tb5brvimprc3ku05/2196429234.pdf
    • http://chothuexehochiminh.com/userfiles/file/42759563347.pdf
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/42820699271.pdf
    • https://mziagroup.com/wp-content/plugins/super-forms/uploads/php/files/77l375f6tp33d16fo3semtbv5n/66954695128.pdf
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16073c5c908bbc---57418726257.pdf
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/xogudenabeziluma.pdf
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/511077087c0bd1c5d3885c7871512cf1/guvaxizez.pdf
    • https://rittenhousesmiles.com/wp-content/plugins/super-forms/uploads/php/files/40d7fe325414d86db3e2972302379e1c/fazujerajinikegofomagi.pdf
    • http://digitalqwerty.com/ckfinder/userfiles/files/jolugeridi.pdf
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/jgrfqsgoidinffje477atjj4ve/59385946618.pdf
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160bb52ad8e5cc---44023698665.pdf
    • http://bibliotekaludwin.pl/img/upload/files/15022302936.pdf
    • http://allycatering.com/userfiles/83379508074.pdf
    • http://garageanything.com/js/upload/files/73176815969.pdf
    • http://shsclassof1959.com/clients/a/a7/a7a82b2a6025f7fafce5d77be70bf845/File/32205914731.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_off0000f507.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF507 16792 bytes
font_01_sfnt_off00010d19.bin
105ae4a1da5b0e6f6f8208cacea6b3a4cc6d73c266f2cf09733d8b56d2d9cb9b
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D19 19480 bytes
font_02_sfnt_off00013f43.bin
622dcb78738c84a2de0f5a6e12dd5bd75e1a7f294864a5fecfd79e249ce7ea05
pdf-font-stream PDF embedded font (sfnt) at offset 0x13F43 10792 bytes