Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4bcee4846b5aac0…

MALICIOUS

PDF

97.5 KB Created: 2021-09-12 15:08:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2c75e53cc98a15ee59817530b7f1f8ac SHA-1: 6abe7b795463856691f40bf31e3b54c6822ac124 SHA-256: f4bcee4846b5aac097b965444b94550d20abc8f6db54854dd60ec64824cffab6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as containing a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing trojan. The document body is heavily obfuscated and unreadable, but the presence of numerous external links suggests a phishing or SEO poisoning attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://www.nachtruhe.info/up/files/tekeluzixidara.pdf In PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/l4ikpie1f13muk27vqc0b3stg3/45201501583.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/16138c22d8a259---bifawovadijugenuso.pdfIn PDF document text
    • http://salkim.com/userfiles/file/riwijorimukibimuvogobi.pdfIn PDF document text
    • https://regaluxiluminacion.com/uploads/assets/file/50422087989.pdfIn PDF document text
    • https://samsungklima.net/upload/ckfinder/files/97373341352.pdfIn PDF document text
    • https://nichecnk.leaddeehub.com/userfiles/files/joxuvibakivudejesawobur.pdfIn PDF document text
    • http://prime-standard.com/piceditor/file/1772892191.pdfIn PDF document text
    • http://rosg.net/sa_upload/userfiles/file/20210905164829.pdfIn PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/go3k2ho59v706j9i3pi1rhsct5/20800101435.pdfIn PDF document text
    • https://tselectromechanical.com/uploads/CKfiles/files/dokawokatirajajum.pdfIn PDF document text
    • http://kowalstwwo.pl/public/cms/images/file/88473767883.pdfIn PDF document text
    • https://www.pactforfamilies.org/ckfinder/userfiles/files/36150930635.pdfIn PDF document text
    • http://www.gyndoktors.de/ckfinder/userfiles/files/papojipifat.pdfIn PDF document text
    • http://rvhifi.cz/files/file/sewojajikugetazasemor.pdfIn PDF document text
    • https://shindah.com/images/ckeditor_img/files/jomemuxuxamolefopelejer.pdfIn PDF document text
    • http://ceramicaartisticamarsalese.it/userfiles/files/96656253522.pdfIn PDF document text
    • http://jyjjapan.jp/files/ckeditor/files/74610803090.pdfIn PDF document text
    • http://standardamulet.com/files/files/zabozivanuwiri.pdfIn PDF document text
    • https://kalashad.com/userfiles/file/vipizebewurinax.pdfIn PDF document text
    • https://gkatsov.com/userfiles/file/39777137502.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/57skncgij1v2h0sunmset7t894/67819481535.pdfIn PDF document text
    • http://liqaa-lb.com/files/userfiles/files/75540230114.pdfIn PDF document text
    • http://alicekhenrylawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/11343056630.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=redmi+note+9+captured+photosPDF 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_off000115c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115C1 11048 bytes
SHA-256: ec1b47a8837741a3a7080b3f1cd94206611f0312e170e1ccd749c3f5f37e0cd1
font_01_sfnt_off00012f4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F4D 18896 bytes
SHA-256: fd2c581465de043499fc43321a8fdbf570c5092c9bd5edb5310c280c08eea11a
font_02_sfnt_off0001603e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1603E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1