Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb6355f27b20772e…

MALICIOUS

PDF

80.3 KB Created: 2021-09-13 22:57:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4fcdfb2ba517220642afef15a2c373f2 SHA-1: a39cf4ffbd7dce737c6f61f009864ded37f07698 SHA-256: fb6355f27b20772ef7079d2e057d16eee72d1b3d38fbfa7e17cf593f3a0f10ff
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 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. While no scripts were extracted, the PDF structure and URL analysis point towards an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://taxfirma.com/userfiles/file/89021423285.pdf In PDF document text
    • http://eortak.com/img/fck_temp/file/tolanetegi.pdfIn PDF document text
    • https://washlounge.in/ckfinder/userfiles/files/dojavi.pdfIn PDF document text
    • http://saigondome.com/uploads/userfiles/file/20202189722.pdfIn PDF document text
    • http://lianbang123.com/uploads/files/202109011601108445.pdfIn PDF document text
    • http://kleiberit.ru/files/file/34519805513.pdfIn PDF document text
    • http://psn-monolit.ru/img_file/files/wanedekifuvopano.pdfIn PDF document text
    • https://unchiulmihai.ro/files/fckeditor/file/94375292756.pdfIn PDF document text
    • http://meteosputnik.ru/userfiles/file/35331908438.pdfIn PDF document text
    • http://krishikhabar.net/assets/ckfinder/core/connector/php/uploads/files/41636314897.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613b99b7bcecc---24175602801.pdfIn PDF document text
    • http://lachina.cn/upload/file/kuneduxojomi.pdfIn PDF document text
    • http://autowassenindex.nl/images/uploads/wamemosojez.pdfIn PDF document text
    • https://rozynoklinika.lt/userfiles/file/lalorivizuzimeziwidopore.pdfIn PDF document text
    • https://mebelihome.ru/upload_picture/zuziragudafixorekokefoz.pdfIn PDF document text
    • http://ozdesignhouse.com/app/webroot/uploads/files/nixogegorivibunakodepepub.pdfIn PDF document text
    • http://www.sushmitamukherjee.com/fckimages/file/61099666075.pdfIn PDF document text
    • http://st-ark.it/userfiles/files/90533140489.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613379e62b199---56886984675.pdfIn PDF document text
    • https://cmfnepal.org/userfiles/files/zolikefesoxetimanimuneg.pdfIn PDF document text
    • http://systempro.kr/userData/board/file/70966521052.pdfIn PDF document text
    • http://arucax.am/user_images/file/nufepowezajafili.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16137d2102d74a---zituzidopifeta.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=birdie+golf+app+androidPDF 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_off0000d64b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD64B 17880 bytes
SHA-256: 0ee3f3df3b23749ae7c2cf4af9eddc424caee208a3b7736b1b69d000a9299f80
font_01_sfnt_off00010457.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10457 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C6E 10460 bytes
SHA-256: 03fac69842b7a8770b36b595e8bf2297739f0f936c5c8dca888fe7f3678a62ed