Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf8578c8120da479…

MALICIOUS

PDF

85.8 KB Created: 2021-07-05 23:02:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 2a5bafd0f55b43de8b66cf2d0e3d8ab6 SHA-1: efab45033b6a4e37ead6693df1e78391a91dbce8 SHA-256: cf8578c8120da4796d7ae30872332043c84a5c135af6ff6fe72c23c4ef99b028
96 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to numerous compromised WordPress sites, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier also flagged this PDF as malicious with high confidence. The document body is heavily obfuscated and unreadable, suggesting it's not intended for direct user interaction but rather to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://lostsoulsmemorialnj.org/wp-content/plugins/super-forms/uploads/php/files/096319dbb758ce114040e028ed3a3f78/muwebufe.pdf In PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a22dd85c8ab---49798617867.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160bd4b7f26c94---24149320195.pdfIn PDF document text
    • https://www.demetagras.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce3cd346e4---webubirakolimip.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/8951f9ed53dbac2f1a4afa16a430a815/29195033958.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/a614d31b9ccdca33c0559659501d26d7/63062194967.pdfIn PDF document text
    • https://agronlogistics.com/userfiles/files/bubonuteluz.pdfIn PDF document text
    • https://liur-krd.ru/userfiles/file/dotupezenixojojavebukofap.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e0835ed7e6---sesutexa.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e0fc8ec7887---tesivifadop.pdfIn PDF document text
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/fdki3pb7nimp5rt1hhe8j7r26f/zukapapi.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/4dc011fe32ffe593eb3fc30eb3892ce0/81701141633.pdfIn PDF document text
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c91cd07dbeb---telibabifimewejumobuf.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce8c546f0f---dusukupazuwufa.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/gijokuzex.pdfIn PDF document text
    • https://glearningsolutions.com/userfiles/files/80456230409.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5a0b2eb1c5---28798098428.pdfIn PDF document text
    • http://fogathajtohirek.hu/fckfiles/file/megizozuf.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/16081817dbc01b---45086239520.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/160923305a7dfd---81810600898.pdfIn PDF document text
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/buipfk1jrjr50lp2igdan8lnim/14906867809.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090c30f07baf---mivukofa.pdfIn PDF document text
    • http://zonazero.es/userfiles/file/dutakuluk.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/bfcb83c118db3a3040cf2a1f8670f94d/suvajidakizobalami.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/d20e91b71b1413554f689eafcd47002b/89046389278.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=spanish+infinitive+formPDF 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_off0000e9ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9FF 17984 bytes
SHA-256: a00a7025a2647073e3dbf269c527a68ef7e6f7d3582716bf00f9728826677084
font_01_sfnt_off000117ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013006.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13006 10720 bytes
SHA-256: e9060d227f62978668beeaf2544a14dc6ef81fed00eca65b65a02e7ee9effce8