Malicious PDF — malware analysis report

Static analysis result for SHA-256 af6927f2ef1d90b9…

MALICIOUS

PDF

76.2 KB Created: 2021-06-08 00:58:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: fe94aac63a1643a0842e9ac5b0ac82c8 SHA-1: 7151e94c1b6ab341e9c20e41f97b09ea41fc77ab SHA-256: af6927f2ef1d90b9ef7af881f58154ad2052b682a5432c63b8b2ec01782a7295
226 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a fake-CAPTCHA lure. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • 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://krisoc.ru/pbw?utm_term=the+midwife%2527s+apprentice+chapter+2+summary PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4425727/normal_5ffff0c053ce3.pdfIn PDF document text
    • https://luxexawasoju.weebly.com/uploads/1/3/4/1/134109261/betodoboritufa.pdfIn PDF document text
    • https://rativebexatu.weebly.com/uploads/1/3/2/3/132302992/4512710.pdfIn PDF document text
    • https://fixugosotodig.weebly.com/uploads/1/3/7/5/137518485/33fe9e05f49.pdfIn PDF document text
    • https://wigabededonekan.weebly.com/uploads/1/3/0/7/130740374/6050d1a676b75d7.pdfIn PDF document text
    • https://kusudojisopev.weebly.com/uploads/1/3/4/7/134774064/51907.pdfIn PDF document text
    • https://wosefekolejareb.weebly.com/uploads/1/3/4/3/134340916/bimupelewaso_funepunitot_fozifizojig_dopomo.pdfIn PDF document text
    • https://zakogekumepaxu.weebly.com/uploads/1/3/4/5/134598029/5016343.pdfIn PDF document text
    • https://mowewudogib.weebly.com/uploads/1/3/5/3/135310369/muwitezoxefavojifa.pdfIn PDF document text
    • https://winulovovitazu.weebly.com/uploads/1/3/0/7/130740324/92a37e225.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4391920/normal_5fc6b821dd594.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://pokatufaxi.pbworks.com/f/who_owns_the_federal_prisons.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c785ddc8-3d34-43cb-986e-598008c1cb73/onepress-plus_wordpress_theme_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3f8b2f67-2397-4bdf-b171-d4b0a02f7ea1/xirikedopiniwitajewoferit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/66b8b957-2268-4f6f-8c32-7df580dc087a/what_apps_are_on_xfinity_x1.pdfIn PDF document text
    • http://jajisaparev.pbworks.com/w/file/fetch/144419517/wukotugemovifek.pdfIn PDF document text
    • http://bikopatepo.pbworks.com/w/file/fetch/144819957/ripped_in_90_days_workout_plan.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ccd91e19-8ee6-44bc-bada-34a107678654/zumef.pdfIn PDF document text
    • http://visetululiv.pbworks.com/w/file/fetch/144423117/79435374831.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9a5cbfb9-93f5-4dde-b534-a670164a8698/free_grade_3_addition_and_subtraction_worksheets.pdfIn PDF document text
    • http://fudotedafeji.pbworks.com/f/como_aumentar_mis_senos_de_forma_natural.pdfIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e8ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8AD 5672 bytes
SHA-256: 7f00c285153fd8cc4bae3a28076dfd3f98f5be1d7f8d5608520b091e6c611f62
font_01_sfnt_off0000fbf0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBF0 11144 bytes
SHA-256: 9669c2e4185a9f7405ad48396ae542355052c958c59afe79d6bf86ea6b4874e4