Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9d927da53a4dc8a…

MALICIOUS

PDF

83.5 KB Created: 2021-09-06 02:01:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 8017e4703e93bf355a0f373bb732b887 SHA-1: 48801abf040714aaa95b89e36d19e3f719ce8594 SHA-256: a9d927da53a4dc8a033f7055263a3cb4c5af41b48bc07fa30d7d82ca10a90b29
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the heuristic firings and URL analysis confirm the document's role in directing users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://pollackmihalyiskola.hu/ckfinder/userfiles/files/75274637893.pdf In PDF document text
    • http://nathulaldasptti.com/ckeditor/ckfinder/userfiles/files/rinezuwig.pdfIn PDF document text
    • http://phs60sand70sdecadesreunion.com/clients/880504/File/levaputekadedamewosuxunu.pdfIn PDF document text
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/02na3s1vdqak2ngrkppip0gjr4/desajuwokaniguwexa.pdfIn PDF document text
    • http://srihemkuntsahibfgp.org/hemkunt/userfiles/file/leburaver.pdfIn PDF document text
    • http://virtualcharityevents.com/vce_cake/files/files/vararufusiziditi.pdfIn PDF document text
    • http://uelzecht.lu/userfiles/files/81158552114.pdfIn PDF document text
    • http://virtualcharityevents.com/vce_cake/files/files/71725230480.pdfIn PDF document text
    • https://www.psalighting.com/wp-content/plugins/super-forms/uploads/php/files/bee7ea60cba5e3438ac90473ea3dcd85/jokizibegigewoweka.pdfIn PDF document text
    • https://www.blondel-bois.fr/ckfinder/userfiles/files/ginisisazuxofarijukuviz.pdfIn PDF document text
    • https://novahealthclinic.ca/userfiles/file/91216004466.pdfIn PDF document text
    • http://entryexpress.online/chapter_images/files/koxoxumiku.pdfIn PDF document text
    • https://pingthye.com/userfiles/files/punanof.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/htev8tq13e3ndi307q0glv8rp6/vapupiwubo.pdfIn PDF document text
    • https://barcelonacentremedic.cat/files/galeria/files/nubalubotowomez.pdfIn PDF document text
    • http://gymostrov.org/gymostrov/userfiles/file/bisisimanitobukog.pdfIn PDF document text
    • http://lushexperiences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8f63e021c---97993132547.pdfIn PDF document text
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/65519dc85dbb3711fbb968eb9f1340fe/koxovozixanupanudipemefof.pdfIn PDF document text
    • https://mobistore.co.nz/wp-content/plugins/super-forms/uploads/php/files/9c17df9f2d58af381eab85023603ed0d/65717719861.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/160badbb4a668c---jutolobeg.pdfIn PDF document text
    • http://shepardinteriordesign.com/rw/upload/file/29851116218.pdfIn PDF document text
    • http://gocreate.termall.pl/upload/fck/file/90831110141.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609902457428a---38527989280.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fdfe561d890---sekol.pdfIn PDF document text
    • https://deesudcoolingtower.com/userfiles/file/91531954727.pdfIn PDF document text
    • http://gitimohammadilakhimpur.org/ckfinder/userfiles/files/48380888435.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=combinatorial+optimization+book+pdfPDF 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_off0000df6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF6D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f784.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF784 10680 bytes
SHA-256: beb8d0171396fc577fc0ea1267f42981b8fde0b0af1e5860aa7950fff440eb36
font_02_sfnt_off00010fbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FBE 18564 bytes
SHA-256: 988bd169d442c12fe72e5bafc07f7566a121805a83087df59dc36644fac1e3cb