Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1bff303e4c624e5…

MALICIOUS

PDF

78.4 KB Created: 2021-06-11 13:08:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: d1cfaba2d02d7dbf7de3317ca8dc9a94 SHA-1: 410a17933f117f2f9b72a9d81af2c4f539046edf SHA-256: c1bff303e4c624e57527d04c8d20267113049d8476fd011a5e69be30e88fc84c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous URLs pointing to compromised CMS upload directories, suggesting it's designed to host or redirect to malicious content. The presence of external URIs and the overall structure point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://coretry.ru/uplcv?utm_term=kso4+ionic+or+covalent PDF link annotation
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609847c058446---80584330656.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/c943ca6b8ac8c9bccccd3442076c04ee/fudalonunijununabi.pdfIn PDF document text
    • https://btsmstlucia.com/atomicsteps/upload/userfiles/file/94793005492.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160928eb0a339c---kezowig.pdfIn PDF document text
    • https://www.electriclighting.com/wp-content/plugins/super-forms/uploads/php/files/dad681afdc9c239b3f1b393cdf961912/79451168873.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a045e45ebef---91037863357.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a9b052a3780---19686949125.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160843f10e1481---jifosizesetide.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160811643338fe---lesekelum.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/xafiledujesexoru.pdfIn PDF document text
    • https://audreyheselmans.com/_files/file/30461841945.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/5610d2c9a4194870ecc7de65435c3b1f/zeguguxasomexado.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/df0d158ca6f60f777e6f586ad64d7fd6/xuwejubep.pdfIn PDF document text
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/l6o31v9jndabupg4v3ioblh2e2/vezimerozezebenikalak.pdfIn PDF document text
    • http://stellamaris.cz/userfiles/28841280210.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/298ae55k2dpj86gr8grnn1qha1/84908060968.pdfIn PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/fvg1fjlj8go4alhp1u425m8e9v/82144427804.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/8cscdpuaf74crrn678dp4ohpd2/70076090739.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/3430bc4822e6da4db40622b83dc1b8a2/getupaxupavedenekurowulin.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f94e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF94E 4908 bytes
SHA-256: faa107929c4c59e4606be98f6274fec3c78059062d050bc0802fe4b60187c127
font_01_sfnt_off00010a23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A23 10056 bytes
SHA-256: 5362afba3d9ff60167169a2ff709e4480d0ff6d8480ce11fa2f64f7160749dc8