Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5e10fc2d7ba8acd…

MALICIOUS

PDF

92.3 KB Created: 2021-07-05 11:15:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8a61688371c224982d30c4f671a86b35 SHA-1: 71c55ad33d3786baddb9aaa5f298899c61ed5b99 SHA-256: f5e10fc2d7ba8acdcbefeff5b1c72cfcafc6a685cdc7ecc4e2df750d9ebc7cc9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to compromised WordPress sites and other disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. Although no scripts were explicitly extracted, the nature of the URLs and the 'link farm' heuristics point towards an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

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://krisoc.ru/uplcv?utm_term=treble+clef+note+names
    • https://maxflowfans.com/userfiles/file/64908636061.pdf
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/2ae30ed903fa0fbdca0a6192fd6e3ecc/koker.pdf
    • http://utuin.net/files/fckeditor/file/17827398788.pdf
    • https://pinpointfeedtech.com/ckfinder/userfiles/files/jorol.pdf
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/160ba164b16096---zasukekizona.pdf
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb48d0b4b3---40387930706.pdf
    • https://acryl-bg.com/userfiles/file/17911935137.pdf
    • http://www.tramag.pl/upload/file/78830727109.pdf
    • https://newtech-utm.pl/userfiles/file/javebunixeg.pdf
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f05bec3b83---putukigonepozebofosifol.pdf
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1609561b6cba8a---68518168757.pdf
    • http://jkohut.pl/file/fazavizegedalaleweviwez.pdf
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/160760cb631eec---72316604349.pdf
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/mrh0evm5o4ha3n66m1eenmvak5/75723905220.pdf
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/9i9jt04u38n7qakd0hqm3putpt/buloxonax.pdf
    • http://meble-tk.pl/userfiles/file/18829325042.pdf
    • http://www.supercarrentalsofmiami.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a22b726441---85857979603.pdf
    • http://svazekobciorlice.cz/userfiles/file/18751672260.pdf
    • http://coytex.net//ckfinder/userfiles/files/xasasu.pdf
    • http://lakshimi-kaatsu.com/user_data/packages/default/imgfiles/3405968772.pdf
    • http://ypperfect.com/ckfinder/userfiles/files/mubotawuwexatujajesaxoxen.pdf
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e9b39075a3---dufon.pdf
    • http://djpress.pl/Image/files/65477820336.pdf
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/a885l12h7ui6mibdu00k3q8kp2/jasesimezikaligi.pdf
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/2crho5uf8sfibvr0i6gkk6js8r/55528784225.pdf
    • http://magendans.com/imagefiles/file/48649557038.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_off00010510.bin
2c5cd6bef7c78f95aff9265bff8c5bf65a842fb52bc6f23768d1fc0c18c2575a
pdf-font-stream PDF embedded font (sfnt) at offset 0x10510 10508 bytes
font_01_sfnt_off00011d04.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D04 16792 bytes
font_02_sfnt_off00013516.bin
030b2e78b0572491f9db6b5c8d3b6d666f6dab1e15933ae1d63726eff6a64676
pdf-font-stream PDF embedded font (sfnt) at offset 0x13516 18152 bytes