Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5bb28ba1187170f…

MALICIOUS

PDF

94.6 KB Created: 2021-08-11 20:45:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c96d4d5e4951a4be0fd61281326d9f2d SHA-1: 86d4d85944eef1c2feaf076bd1ac12bf3b89ea6a SHA-256: a5bb28ba1187170f818a87f0601e23099c4eb16f652b231b9b089863a3532bf3
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, with heuristics indicating a link farm pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7dc58b5ff---13216632254.pdf In PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160831fd617136---9696325133.pdfIn PDF document text
    • https://www.straightmyteeth.eu/wp-content/plugins/super-forms/uploads/php/files/e4138659440d9baa392935472f47e728/49613674901.pdfIn PDF document text
    • http://ambulatorioveterinarioscapindandrea.it/userfiles/files/89011920523.pdfIn PDF document text
    • https://chandrakantmusicacademy.org/ckfinder/userfiles/files/62851205853.pdfIn PDF document text
    • http://turatabor.hu/media/81353926463.pdfIn PDF document text
    • http://www.anclupnapoli.it/userfiles/file/85964311859.pdfIn PDF document text
    • http://abimobiliare.pl/pliki/File/tegisolasagenebuf.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093e57607474---ruxawila.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/on7p73c8cqpjamjn1tac687f25/gakobipal.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/tv1uptlbau7sjfmi6p6isdjpub/korukatapo.pdfIn PDF document text
    • http://connect-senior.ch/uploades/userfiles/file/worudujafivebuno.pdfIn PDF document text
    • http://myapartment.de/web/editor/files/piluwozogisenuluf.pdfIn PDF document text
    • http://iamsong.vn/uploads/files/5786593983.pdfIn PDF document text
    • http://bilmatbasim.com/userfiles/file/kiwefodupofeganidezu.pdfIn PDF document text
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/e12d6c321398e1df0732910d212100f7/16593640768.pdfIn PDF document text
    • https://carea2plus.com/wp-content/plugins/super-forms/uploads/php/files/92f128eb255d672aacf0e1c2e8f33baa/49549582538.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16077c6c0b80d0---danebifozibu.pdfIn PDF document text
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/a47gh2807gumlqu7g5vi24g4lt/62180606567.pdfIn PDF document text
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/1f3b1f46b0906b1ec880bdf78641aeac/samafuwomizetizesezusud.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/pdfsa9c6pu4tqr7d2v4gpfg16f/zikulunefu.pdfIn PDF document text
    • http://ddaengshop.com/ckupload/files/57498619452.pdfIn PDF document text
    • http://aven.su/userfiles/file/sajopimiwidazexituximodu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=movie+43+pelicula+completa+en+espa%C3%B1ol+latinoPDF 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_off0001065f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1065F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011e71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E71 19496 bytes
SHA-256: f2edc78edfec67fe64305b25fa1de1825b8ce6bf84885a93aaf801d438b0f787
font_02_sfnt_off00014ef9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14EF9 11048 bytes
SHA-256: 83fc265530281e45ca467d59c3d55fd09f37417ad701cf446205eacbbe9c06fb