Malicious PDF — malware analysis report

Static analysis result for SHA-256 f511f5fa98f381ca…

MALICIOUS

PDF

79.9 KB Created: 2021-09-01 23:24:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f7700800aa3b8142f049194914cbfb64 SHA-1: f3494f821ce7773f64681c89d9c826c8984e154c SHA-256: f511f5fa98f381ca17dbf9b5587936b13da56da0da8c55c9ad7f933d1f0fa48f
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting. The ML classifier strongly indicated maliciousness. The primary function appears to be acting as a link farm, likely to manipulate search engine rankings or to redirect users to malicious content hosted on these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

Heuristics 5

  • 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://krisoc.ru/uplcv?utm_term=old+town+temecula+ca PDF link annotation
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/16077420707835---68824346658.pdfIn PDF document text
    • http://graciaindoutama.com/kingkong/userfiles/files/82473979282.pdfIn PDF document text
    • https://lamaisonducoeur.ca/upload/editor/file/44853055563.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/161180c8bea8ee---2122738593.pdfIn PDF document text
    • http://hasyo.net/files/file/19268552293.pdfIn PDF document text
    • http://gzmzwl.com/Uploadfiles/files/rozotovakomebunuxamegeza.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b9c70403f83---dewitij.pdfIn PDF document text
    • http://pokrowce-ochronne.pl/Upload/file/vewerunanijige.pdfIn PDF document text
    • http://ilyxrace.com/userfiles/files/86108280082.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/5k3ifdda26ae5pfgon7fe1pc0p/wiwaralimabug.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a733ae5c1f2---36680223432.pdfIn PDF document text
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/rd79h73rfo19bhhndlodpb3a63/gamajipedevini.pdfIn PDF document text
    • http://web68s.com/upload/files/79205957344.pdfIn PDF document text
    • http://artside.org/data/temp/file/jifukojorelujutosobokoxon.pdfIn PDF document text
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/88f626cb2158e53c6b3d7d9fa7613b0f/25697679921.pdfIn PDF document text
    • https://socialacademy.gr/wp-content/plugins/super-forms/uploads/php/files/eee8cfd6358572715e06aded5ea9d94d/maxakavafemerasometisan.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/83c9317315a42f5ddc3d158d8dc2602e/28806893653.pdfIn PDF document text
    • http://studiodrago.eu/userfiles/files/fevasakonenaninox.pdfIn PDF document text
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/vlbiesrnkej9ddsl4q7kaqccv5/varosoluwus.pdfIn PDF document text
    • http://lawngo.net/fckfiles/88269871849.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607fccdd402a2---27576476548.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/879196a0f95be13e38abca7dc7b7f8d3/78073396618.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/895945fa906e2c073d4e3b510e763e9b/86639979443.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://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_off0000d31d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD31D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eb2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB2F 17900 bytes
SHA-256: 32242e2120fcccc2732a7cd6f498d7c67e7959b7abe5ca6beefe16535cb55a80
font_02_sfnt_off000119f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119F9 10384 bytes
SHA-256: 37131419bf6c1295add491092aa47f3ebfd23647b330267515e98b9c4cb00de5