Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b2b4e67c51d2343…

MALICIOUS

PDF

75.5 KB Created: 2021-06-10 16:42:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: fa4b4be590ae2e3706138ff77420931a SHA-1: 7c308c85927430c19ba00b8b86e6a53770af4c7b SHA-256: 1b2b4e67c51d2343a177bdb2b0ffe15bcb33010a6447c2fb4c4e45865e6f7c50
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file is identified as malicious by ML classifiers and ClamAV, indicating it's a phishing or trojan delivery mechanism. It contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm used to distribute malicious content. The document body, though heavily obfuscated, contains keywords related to textbooks, likely a lure to trick users into downloading further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://chcial.ru/uplcv?utm_term=mathematical+proofs+textbook+pdf PDF link annotation
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e182065885---97073526074.pdfIn PDF document text
    • http://prof-cosmetics.com/upload/files/12983752636.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c87af0bb2d---nupipemukaxazuvop.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079dbbaae4a8---sisev.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/c44aee8641fa43b206eb9236923c3baf/tudigo.pdfIn PDF document text
    • http://agendaalzheimer.org/files/galeria/files/sitixiponoguvefejudevas.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/dasomiwenuzosagilonufa.pdfIn PDF document text
    • http://www.sport-konyv.hu/userfiles/file/vupegupetolojojat.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073b675bfc0d---66870126392.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607f0ef570d8a---89205800838.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/fag0jm69mdeasro2cs37gm7vj1/kutaretinixonuvuxoruzow.pdfIn PDF document text
    • http://www.redactordecontenidos.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16093aaa801fc6---davotenusizer.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/dedd9ffcc1234800a53e5d6204800fb9/39020305105.pdfIn PDF document text
    • http://accomplishtheimpossible.com/userfiles_ati/file/nawepatuxuzaz.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160ac10b1b5700---katobusepifagax.pdfIn PDF document text
    • http://hoondb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c075dec9fe---65294980167.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/a3f1a20317a654d10788dd8d38ce8265/12186496686.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e9c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9C3 5672 bytes
SHA-256: f37a853d5ba865c02c90486d6ea2e234f6b1d59a797ef49db83c9cd1fa19b27a
font_01_sfnt_off0000fced.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCED 10540 bytes
SHA-256: eb87e882d99220c40cbb24586f697c514bf4fbc313127eca260342140d2b7a56