Malicious PDF — malware analysis report

Static analysis result for SHA-256 6351c80b89fa7c9b…

MALICIOUS

PDF

93.2 KB Created: 2021-06-27 09:10:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 0bb217e33d634d89664756f6f924c234 SHA-1: f671d70825b038356abe1fe497f7a8bb67844b95 SHA-256: 6351c80b89fa7c9b64653c4253bd1e36acc27631383dba82c9d275944813d138
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress upload directories, suggesting it's part of a link farm designed to redirect users to malicious sites. The PDF structure and the nature of the URLs strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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 http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d7955bf238f---zaxomurimuvo.pdf In PDF document text
    • http://www.abcklima.hu//data/editorfile/zoxisurumizavabutamo.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd077edbeb---97086275343.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/5u0iq376d5tg5jjd6grjd1d398/82153358362.pdfIn PDF document text
    • http://taiwan-casters.com/userfiles/file/pilubebujuzovajerunapuwe.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a4d509bb913---derifitulusubuja.pdfIn PDF document text
    • http://israel-aliya.com/wp-content/plugins/super-forms/uploads/php/files/3af9948a6b2c4872163b9c99983af414/tunofenupigemomel.pdfIn PDF document text
    • https://fototipia.hu/files/files/12688839598.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607c96ade37c5---wamapom.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a567b2ea85f---maxijapanawexabod.pdfIn PDF document text
    • http://banghaija.com/userfiles/file/80999095868.pdfIn PDF document text
    • http://gyobel.itpublic/file/13497725794.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/jimek.pdfIn PDF document text
    • https://micast.de/wp-content/plugins/super-forms/uploads/php/files/hht11qh5nh0piob3b6igemmscm/88085083210.pdfIn PDF document text
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/6e8qm9mdl93ek612advjjb47pn/57028709459.pdfIn PDF document text
    • https://adamant54.ru/userfiles/files/runutotojudewesirakuk.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfcfe9e15ca---49400722278.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aadb7f96b69---tanibonosadikeriwe.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/160afb7b04b434---mitekekamitefago.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf2b007278e---29663423690.pdfIn PDF document text
    • https://bilegt.mn/userfiles/files/tumamaj.pdfIn PDF document text
    • http://k-yoga.org/file_upload/spaw_upload/file/20210510054002.pdfIn PDF document text
    • http://shhs69reunions.com/clients/e/e9/e92da0bc0099326815942f81a5c18dfc/File/53846460323.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160d1f20a1bfb2---zusamadur.pdfIn PDF document text
    • https://carstenrath.com/wp-content/plugins/super-forms/uploads/php/files/ioh7iesafjhfkmrf87jta2f8ul/38565556439.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/cn9ua21t0thlbctr0ineah8cuh/71176529966.pdfIn PDF document text
    • http://alhouti.com/userfiles/file/98512251873.pdfIn PDF document text
    • http://arisutour.com/ckupload/files/91791635416.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=famous+sonnet+of+william+shakespearePDF 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_off000106f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106F6 10876 bytes
SHA-256: 91eff3d2164a5d39386814230e5de0a84da7be7be2bcdf0efc117ceca39eaa27
font_01_sfnt_off00011ff7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FF7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013809.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13809 17288 bytes
SHA-256: 8782e38688e2d64cee4aba89b7f331254e72e99c86472865b296c68229328494