Malicious PDF — malware analysis report

Static analysis result for SHA-256 8dd841f9a1c2800e…

MALICIOUS

PDF

91.0 KB Created: 2021-09-06 16:38:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 700677dba68e5da8a3f1068a6bee6ac0 SHA-1: 5fda029ba1ac17ae36d947b8dc95063fda66ccdc SHA-256: 8dd841f9a1c2800ecc054a0b92f125b5d006fdb6e2841f67003e263e371ee5a5
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to compromised or disposable domains, indicating a link farm designed to manipulate search engine results or direct users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://liantoong.com/archive/upload/files/vuzag.pdf In PDF document text
    • https://triptoboloyfoundation.org/editorsfiles/files/92463653455.pdfIn PDF document text
    • http://swatimishra.in/uploaded_files/userfiles/files/berobovakitavutawej.pdfIn PDF document text
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/2a59d2649489db5e6f045b1d25190dfc/sopejajasemavuru.pdfIn PDF document text
    • http://proxima-design.cz/files/file/98870177192.pdfIn PDF document text
    • http://cablexconsulting.com/Upload/file/sidutefebakutadiku.pdfIn PDF document text
    • http://wojno-stal.pl/pliki/file/ziburofijafiwudunemeso.pdfIn PDF document text
    • https://grand-forge.ru/wp-content/plugins/super-forms/uploads/php/files/166273335f49e003f6f3cbb1e1dea27a/vapujikadazeg.pdfIn PDF document text
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/peredijala.pdfIn PDF document text
    • http://alternativecarrepair.com/userfiles/file/76811731345.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/da48f49051d1c0842d2f247054f3b808/kevepupamajomujadijixirem.pdfIn PDF document text
    • http://brmxn.com/userfiles/file/20210702041206_owmm9s.pdfIn PDF document text
    • https://verticala.ro/images/userfiles/jukegiwevev.pdfIn PDF document text
    • http://dogalakustik.com/depo/sayfaresim/file/97754983476.pdfIn PDF document text
    • http://vigova.vn/Images_upload/files/52277441905.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086f095c7b3a---xukoxogiva.pdfIn PDF document text
    • http://j-club.eu/userfiles/file/netenoxuzemop.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609231d637864---74962710720.pdfIn PDF document text
    • http://surtek.biz/image/files/20150114_233644.pdfIn PDF document text
    • http://mamnonhieutrung.edu.vn/ckfinder/userfiles/files/37842139234.pdfIn PDF document text
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/adfeb731c609ed1f0a2386d7f6c6e201/43570509754.pdfIn PDF document text
    • http://falerisztika.hu/tmp/wifirufi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=classifying+triangles+by+angles+worksheet+4th+gradePDF 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_off0000f86e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF86E 11172 bytes
SHA-256: c0aac123fe4b0f0340af3fc0eb37bc79fff1fa8ab77a8df97a2c543e6efc8dd7
font_01_sfnt_off00011262.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11262 19164 bytes
SHA-256: 458f0675a40097aaf3440e47675eef5a10803f6a73ea1f05c1a7d36ba1de2d55
font_02_sfnt_off00014417.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14417 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1