Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b52f6fc6b9c5bd2…

MALICIOUS

PDF

87.4 KB Created: 2021-06-25 23:24:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fbb84a004c70fe65067b33d8defac4a2 SHA-1: 8cb6053186eef21d4a0bd41bc5b646bd3e863113 SHA-256: 8b52f6fc6b9c5bd20518bdeba1f754e7c38f7d6831d62fafe591c6ab09401192
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. The document contains numerous links pointing to compromised WordPress upload directories and disposable hosting, suggesting it functions as a link farm to distribute malicious content or conduct phishing. While no scripts were directly extracted, the nature of the URLs and the heuristic firings strongly suggest an intent to redirect users to malicious sites, likely for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://smidgel.ru/uplcv?utm_term=truck+and+auto+auction
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160705a4a6e8f6---35127474562.pdf
    • http://bukharasuwanee.com/sites/default/files/file/2458836629.pdf
    • http://bebelino.ru/userfiles/file/81092151529.pdf
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a529708842c---najevodivoroxewof.pdf
    • https://tort-art.ru/userfiles/file/76652379561.pdf
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1607d8452dbca4---63128118348.pdf
    • https://hifi-markt.eu/kunden/kronhardt/ckfinder/userfiles/files/nugulunejinivuxutubujuwo.pdf
    • https://edbcagliari.it/file/49684320008.pdf
    • https://www.charroninc.com/wp-content/plugins/super-forms/uploads/php/files/072e20b42b91b1f2af2cb5d9035f9117/99381844588.pdf
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/qg00n9k5q20ej7ac93ti8uudih/59632314016.pdf
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad72f01e884---84769726637.pdf
    • http://www.alexgis.com/siteuploads/editorimg/file/kupuji.pdf
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607b7790dd655---28294248242.pdf
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a57506b1790---72151766651.pdf
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/ecd696ed643a8afb4673298564b610bf/defojewusogikifedim.pdf
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072486b277d7---vefasejunawonotini.pdf
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a602dc4f199---ditufafeluzilosumifuwis.pdf
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ece2fa9c79---29104825038.pdf
    • http://steelbo.com/uploads/admins/u0/files/20210609220133.pdf
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/f25f33a42a682610fbfc72434b1bac34/57913578503.pdf
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf65db08563---94672389757.pdf
    • https://avenue102.com/uploads/file/18090683798.pdf
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/f4cl0l8grrggrnsm9vj503sd6f/25763135262.pdf
    • https://www.northwoodmedical.ca/wp-content/plugins/super-forms/uploads/php/files/gfhufc7etp471tponnsfurmhjd/wipexemibepigo.pdf
    • http://aldara-latinoamerica.com/userfiles/file/sewepuwukavabitixav.pdf
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1607e00d677b7f---dalaleje.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_off0000f35a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF35A 16792 bytes
font_01_sfnt_off00010b6c.bin
b76bdbee1045e2571690b27d029fa4d59a39566cfe6d55621703b9afe223c35d
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B6C 17568 bytes
font_02_sfnt_off00013958.bin
a8df22b63b01624f71fbfe174e4a20737e90e2ee18b2e576b9cadb18560577f9
pdf-font-stream PDF embedded font (sfnt) at offset 0x13958 10172 bytes