Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf5870a91f4d2854…

MALICIOUS

PDF

83.7 KB Created: 2021-08-19 11:33:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: 95738b2458016c1918997a6452d62bf1 SHA-1: 02b83aea5c2dc3ee6b28b07e4bb85fcfc6e7006b SHA-256: cf5870a91f4d2854f86665f791478187d6970d8314be4f42ba96e38125aa05ea
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites 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. The presence of multiple external URIs and a link farm heuristic supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://automotiveenergy.cz/userfiles/file/vizodejoravita.pdf In PDF document text
    • http://st-johnson.com/Uploadfiles/files/72918005437.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/81413867183.pdfIn PDF document text
    • https://noticky.net/akce/fotky/file/sunedanudikasadel.pdfIn PDF document text
    • https://almoheetmanpower.com/public_html/userfiles/file/73140561232.pdfIn PDF document text
    • http://xiangzhuan.tw/upload/files/68164168268.pdfIn PDF document text
    • http://mamaskitchenorder.com/uploads/files/65392235605.pdfIn PDF document text
    • http://oguzlarotomatiksanziman.com/depo/sayfaresim/file/51157196583.pdfIn PDF document text
    • http://telegid.tv/userfiles/files/bebaxeguvetesexu.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/7db36cafd0f288aebbbfd0749f047d86/dewapajupewiviled.pdfIn PDF document text
    • http://rockhouseschool.com/rockhouse/uploads/files/wipefuwirovubelopu.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1606e8a64dbfe5---linodapixigo.pdfIn PDF document text
    • https://www.temsilcifirsatlari.com/wp-content/plugins/formcraft/file-upload/server/content/files/160877a8bbd632---zizikovusutu.pdfIn PDF document text
    • http://dogoducthien.com/uploads/files/46068373002.pdfIn PDF document text
    • https://armagedonspedycja.pl/files/file/nabusemasiker.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a960652c38a---68720874966.pdfIn PDF document text
    • https://aluminiosarla.com/userfiles_arla/files/megudodotutimiv.pdfIn PDF document text
    • http://chickenwild.com/upload/contents/images/images/gesajagikorilavutuvu.pdfIn PDF document text
    • https://carea2plus.com/wp-content/plugins/super-forms/uploads/php/files/c07b09bcfb388e5d365c203426030a5e/fokes.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098bb141663e---zefuvovozemin.pdfIn PDF document text
    • http://northcity.rs/slike/files/56349196646.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=rainfall+and+bird+beaks+gizmo+answers+pdfPDF 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_off0000e1d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1D2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f9e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9E4 16668 bytes
SHA-256: 492d2fb29357732dc4edce60b1c6a9daec940ff8e89848bcf13ea55f0fb7cfd2
font_02_sfnt_off00012507.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12507 11168 bytes
SHA-256: 4549c32137385706e0272f7d3281dbc8d4c87d4700ee5d92b4a9adc446160ebb