Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa8181d52e8f4057…

MALICIOUS

PDF

92.4 KB Created: 2021-09-11 01:45:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d442b01ecfd80b129da3b76994f21783 SHA-1: 32d0c26dae56791be60bb786c11705b9662bce1b SHA-256: aa8181d52e8f4057bb03b9a34d55189104f67aab7e9ad0a7eb440f65cabe02fc
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many pointing to compromised CMS upload storage or disposable hosting, characteristic of a link farm designed to redirect users. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a non-clustered link farm on disposable hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/4ed29a830b6aa56026f052c8aeb500b6/30177836505.pdf In PDF document text
    • http://jshtextile.com/UserFiles/file///31099299272.pdfIn PDF document text
    • http://aptekarynek.pl/zdjecia/fck/file/lugira.pdfIn PDF document text
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16135face731e1---zanizobajonagol.pdfIn PDF document text
    • http://baruraprotidin.com/assets/ckfinder/core/connector/php/uploads/files/letimedazejidegi.pdfIn PDF document text
    • http://dungcubepgiangtrinh.com/webroot/img/files/duvavulefokeg.pdfIn PDF document text
    • https://svilia.restavracia02.com/userfiles/file/22601140372.pdfIn PDF document text
    • http://daphongthuyhueminh.com/uploads/image/files/27016381187.pdfIn PDF document text
    • http://xn--c1aejbdnke.xn--p1ai/admin/ckfinder/userfiles/files/janokiwub.pdfIn PDF document text
    • http://parfumland.sk/upl/75079239964.pdfIn PDF document text
    • http://air-separation-supplier.com/d/files/botejo.pdfIn PDF document text
    • https://mwasafat.com/uploads/files/7314851961.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/2259e9fced52ee174604b3f03fca2b2e/7261802730.pdfIn PDF document text
    • https://togeltop.net/contents/files/nerirez.pdfIn PDF document text
    • http://dalnoboy.org/data/filestorage/upload/files/63711904635.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/20ad967c1330ed82c85d89b55b14619a/89566110349.pdfIn PDF document text
    • https://ngonluathan.vn/images/ckeditor/files/kovebojarotusite.pdfIn PDF document text
    • http://sm300159.agchost.com/userfiles/files/sarevuzukubimabikuderu.pdfIn PDF document text
    • http://babyshelter.net/assets/upload/files/rorogarabuvuni.pdfIn PDF document text
    • https://2winit.com/Files/files/garonemexixigivokew.pdfIn PDF document text
    • http://theofficeplus.com/userfiles/file/tagilazidobut.pdfIn PDF document text
    • http://movietek.vn/hinh-anh/files/fagugulilot.pdfIn PDF document text
    • http://ageofwonders.buka.ru/sadm_files/46056659995.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=minecraft+pocket+edition+on+pc+free+downloadPDF 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_off00010279.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10279 18620 bytes
SHA-256: 867b932a6449060b824b223bea6f55f0ff0c9cca84e114b5da00691a5f75f08c
font_01_sfnt_off00013363.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13363 10616 bytes
SHA-256: dd92a860161eca2653031b9447ff208bfc595f0a8955c9b8e8c04e9ab541fe03
font_02_sfnt_off00014bd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14BD2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1