Malicious PDF — malware analysis report

Static analysis result for SHA-256 81a21120124dfc2a…

MALICIOUS

PDF

140.2 KB Created: 2021-08-08 17:36:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: b69f7b3e866f4721f3fd05055ae9ead6 SHA-1: 9d9975156f3b6015bfa338885cc3aed26dde5aa6 SHA-256: 81a21120124dfc2a1709b2a16a00b620b589ec47045d54c63b542fb742809a59
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to other PDF files hosted on compromised WordPress sites, indicating a link farm or distribution mechanism. The presence of these links and the overall structure suggest an attempt to manipulate search engine results or lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

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://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/161066d19a2b55---28729907264.pdf In PDF document text
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070879f2fb9d---fagobexizibagu.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8d99e4a84---musok.pdfIn PDF document text
    • http://chapelguild.com/images/usr/72431809262.pdfIn PDF document text
    • http://alexanderjamesbackcatalogue.com/userfiles/file/52320802988.pdfIn PDF document text
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/06880bc3d658141c26aa68a3b4608d4a/lusatojinapumezisor.pdfIn PDF document text
    • http://baove24h.org/upload/files/40238357626.pdfIn PDF document text
    • http://www.halpellet.hu/userfiles/files/garetisakosegomuvenejil.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a871e8042ab---molawifowuduvidezeg.pdfIn PDF document text
    • http://portalkucharski.pl/app/webroot/media/files/nulakozo.pdfIn PDF document text
    • https://lienlacanien.com/img_pages/file/niwudab.pdfIn PDF document text
    • http://jullien38.com/ressource/site-image/files/71147939200.pdfIn PDF document text
    • http://fusheng-vietnam.vn/admin/webroot/upload/image/files/bejimikudeduvu.pdfIn PDF document text
    • http://salinahighschool1968.com/clients/3/33/33fcb9b832a528c934b1ac42c6b88a99/File/nulajorubodexolowedolo.pdfIn PDF document text
    • http://giaodantanthaison.com/Images_upload/files/wibozowakijij.pdfIn PDF document text
    • http://historia-bfured.hu/userfiles/file/6442695742.pdfIn PDF document text
    • http://scuderieverdina.it/scuderia/userfiles/file/rabofebakamatikapariwaxe.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/1i65pgnpvvmq9elumrbeohq685/86597905606.pdfIn PDF document text
    • http://polskienarty.pl/data/aktualnosci_imgs/file/34314633385.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607b221d9e4a3---80705950380.pdfIn PDF document text
    • http://accessibilite-salle-eau.com/ckfinder/userfiles/files/tikoledewulosilojufev.pdfIn PDF document text
    • http://stilistspb.online/public/files/uploads/files/wodun.pdfIn PDF document text
    • https://plswa.com/wp-content/plugins/super-forms/uploads/php/files/dba09c9abe939cfb7a4f499bae55a137/43067025384.pdfIn PDF document text
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/71cde5fc975e02a35ea2be45a3be62cf/90767803412.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=christmas+worksheets+for+middle+schoolPDF 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_off0001c225.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C225 10848 bytes
SHA-256: 65ace0c28843f5c0001fb8224edf7a75372bea03da08f8f9eb7e9a2ece5e4c8f
font_01_sfnt_off0001db4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1DB4E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001f360.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1F360 17880 bytes
SHA-256: 0739bd7c1df4495efb9a049539fa494e758f30b86fbe2563048368872d96f985