Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f66d2ac2be6d199…

MALICIOUS

PDF

87.5 KB Created: 2021-09-07 06:56:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 13f686f88a8a4da653e173d79f1ba0b6 SHA-1: e95945661c5adca91b7d95ea051ddc40962e5ad8 SHA-256: 5f66d2ac2be6d1994e4fd5146899a8b6857f4e431cb4379701fdce7074ae130b
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs that point to compromised websites and disposable domains, indicating a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious, and the heuristic firings suggest it is designed to leverage external hosting for its malicious links. No scripts were extracted, but the primary attack pattern is the distribution of malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://nomylo.ru/uplcv?utm_term=led+resistor+chart+pdf PDF link annotation
    • http://debandhelder.nl/ckfinder/userfiles/files/31552719947.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b16624640ab---lapugalaru.pdfIn PDF document text
    • http://velocimapper.com//webfiles/file/vujuxabuwebut.pdfIn PDF document text
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b4aaa6d5ea---3515589793.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/dfc788e0070fafac25b2eb0572d1ea6f/12826045516.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/454841f09af9967946b7d7506a365e35/49193156543.pdfIn PDF document text
    • https://bamfieldrental.com/userfiles/file/vamowofeve.pdfIn PDF document text
    • https://avvocatoboretti.it/file/55673605234.pdfIn PDF document text
    • https://anthonygillant.com/userfiles/file/gerogageme.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/bqoc4eos8pnci2a2rgtkpt7s5d/78740644578.pdfIn PDF document text
    • https://mihalex.by/files/files/93654934182.pdfIn PDF document text
    • https://makemycake.gr/wp-content/plugins/super-forms/uploads/php/files/709khhb9mukv90htmj2q5gqljd/wajozexatavosamopudot.pdfIn PDF document text
    • http://petra-dario.info/upload/datoteke/88041467993.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/1c8d4cd5a222f58ce35d955b76bb4927/56623631620.pdfIn PDF document text
    • http://cbelmira.com/wp-content/plugins/super-forms/uploads/php/files/semu0bo0mf8url54khns5n4lq6/lexezovife.pdfIn PDF document text
    • http://misosmile.com/upload/editor/files/63331642627.pdfIn PDF document text
    • http://oreade-breche.fr/userfiles/file/dererakabupuwugomapoxer.pdfIn PDF document text
    • https://chetanaus.org/bheru/uploadfiles/file/41286509181.pdfIn PDF document text
    • http://dwornawodzie.pl/userfiles/file/lodogumodefazazikolozak.pdfIn PDF document text
    • http://photographybynami.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5862d8a084---motosavovaduwujogevutiba.pdfIn PDF document text
    • http://english-life.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607771f0a27bb---ginadoreweju.pdfIn PDF document text
    • http://veterina-hrib.cz/user-uploads/files/natux.pdfIn PDF document text
    • https://petikdaun.com/contents//files/tanemimosudamibena.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b49eda81b10---kovezotatasus.pdfIn PDF document text
    • http://zs.tom.ru/jsplugins/ckfinder/userfiles/files/gutod.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://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_off0000ed20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED20 19436 bytes
SHA-256: ee5fb2368d0fe4be259ef08830856a9c4e86939ea57a88d863f2b353818e9faf
font_01_sfnt_off00012016.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12016 10524 bytes
SHA-256: 331d544f95c505fb7691066214427f53900d2d964230e79d66427944d8770d6e
font_02_sfnt_off00013829.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13829 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1