Malicious PDF — malware analysis report

Static analysis result for SHA-256 28ebf39cb0339e87…

MALICIOUS

PDF

86.0 KB Created: 2021-07-07 19:51:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ac45f30711660a5519b5c6eaa5600073 SHA-1: 49c959d5cc43d70b83720d5ada0c765215dc0fef SHA-256: 28ebf39cb0339e872eabbb3a70be96d535f6def5706fbbe364394ef25dc5b7aa
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites, indicating a link farm or SEO spamming operation. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the primary indicators are the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • 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 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://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/iimcuu7e9m5igctoe7og9l1i33/mutosewedev.pdf In PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1607714b8f0abe---tupusuruz.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/0ba6e637b353521de674193222689635/71250545582.pdfIn PDF document text
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/7816052563.pdfIn PDF document text
    • http://tamker.hu/userfiles/file/xuzepaxoguzabi.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b1aeeb91cb---84020123768.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609c5f1e70b4c---19419106293.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/da5hq0b8vii341ngv1ntdrvsk8/81702457468.pdfIn PDF document text
    • http://arc-en-cielproduce.com/ckfinder/userfiles/files/258899107.pdfIn PDF document text
    • http://euro520.net/userfiles/file/1623316258570597797.pdfIn PDF document text
    • http://skyline1968.com/clients/74864/File/97970661710.pdfIn PDF document text
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/9175fb02f221221a48efde0a878cb2c4/kavonesewisizedipejavolop.pdfIn PDF document text
    • https://calendarsunrooms.com/userfiles/files/sizakifadujosogaf.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/97343177371.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/1609b83aac0550---rixezifugu.pdfIn PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0d2d9df2fd---55282086779.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/35r4hf15do9rp3t942isilvsn2/70936152450.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607aef9f5cf97---doderewafufevojupas.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b78240e8c75---48980474775.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/160797ffec2491---47317475341.pdfIn PDF document text
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/16076fd5872335---mosadawimijot.pdfIn PDF document text
    • http://dogable.de/userfiles/file/99000954700.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079ff0f670c2---lotinapexukoja.pdfIn PDF document text
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/no30l20bg8md65kvkgkh351v4p/11952955760.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/nr0sdncvkm1kt2usm66ljvlc7b/22954082835.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=20+question+quiz+and+answersPDF 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_off0000ee67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE67 16636 bytes
SHA-256: 6553d05ffafe97c6d2606a86a1bc9b93fd9e57e49b7476508aeb989d7b8db2bb
font_01_sfnt_off000119d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119D6 10732 bytes
SHA-256: d0c519670ae066dde2240e4bd3969c9012526ec597fe78b696a0fe171771ac2a
font_02_sfnt_off0001329b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1329B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1