Malicious PDF — malware analysis report

Static analysis result for SHA-256 b626bfeb01e1e881…

MALICIOUS

PDF

122.7 KB Created: 2021-08-15 04:24:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 6d15bb9de2ffbb15448371f3b1a1d244 SHA-1: 2e7e2d0151043a5a96ec28d570e945f2a7509f10 SHA-256: b626bfeb01e1e881fe42513f9370c4f6dde133879b69c08ad7419570edd63908
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is often used to execute malicious actions or redirect users. The presence of numerous URLs pointing to compromised WordPress sites and disposable hosting indicates a link farm designed to obscure the final malicious destination. ClamAV detection and ML classification further support its malicious nature, likely as a phishing or malware delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 7

  • 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.
  • 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 http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c14ce5d3e5---68559169746.pdf In PDF document text
    • http://skolicka.eu/foto/images/file/fudutevaluvipofodotab.pdfIn PDF document text
    • https://nikoljski.com/ckfinder/userfiles/files/zirabelez.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607d6dd43a4a3---42068197781.pdfIn PDF document text
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/5bbda544ee89da4e9c5cfd4892b0e283/fuvul.pdfIn PDF document text
    • https://thietbivesinhanhhuy.com/asset/files/wupidaximux.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1608068ffc7c73---49083743764.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610a9e3d11faa---pekomifa.pdfIn PDF document text
    • http://nbkhjc.com/uploads/202108/file/210813001543888987raw09uyfn0vb.pdfIn PDF document text
    • http://msnladyboy.com/ckfinder/userfiles/files/47967215455.pdfIn PDF document text
    • http://miltonhigh65.com/clients/874455/File/31157273943.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee1f0aca979---28352712005.pdfIn PDF document text
    • http://jinanxintiandi.com/userfiles/files/85219752744.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/160881a8003574---tovavipejegilabivatu.pdfIn PDF document text
    • http://outspokenholland.com/userfiles/fckFile/20210721074506.pdfIn PDF document text
    • http://mankatomnclassof71.com/clients/e/e0/e0e8961458839910853a12af65841b27/File/solawo.pdfIn PDF document text
    • http://www.darvidproperty.com/news/file/daxitibigagukipakene.pdfIn PDF document text
    • https://msr-hudsonproperties.com/wp-content/plugins/super-forms/uploads/php/files/9788a1fdb76f6c367391b414d8b4c1d7/ranomuvedanijituv.pdfIn PDF document text
    • http://skyrunarser.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/210723232630423501da9x6c.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16102b5f3cee97---74384495669.pdfIn PDF document text
    • https://krossi.ru/images/content/files/61372201801.pdfIn PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/2a10b1132384baf0db6dfb52aacb867a/felabuponalav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=anorectal+malformation+journal+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_off00017beb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17BEB 10824 bytes
SHA-256: e102a68e294dd2e2d193c12a64e0efed63d024fdb25eeeda202882f9f03c48d8
font_01_sfnt_off000194cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x194CB 18252 bytes
SHA-256: 4399ea38c53ee5a6c66252cc2406e08434f1bc94077ce84fca2b20cb908007c0
font_02_sfnt_off0001c401.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C401 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1