Malicious PDF — malware analysis report

Static analysis result for SHA-256 f37b1bbb997330f6…

MALICIOUS

PDF

90.4 KB Created: 2021-06-09 16:42:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: c90188a6f0ffb671bd12680468e61fbe SHA-1: 51db32cb77acb56dc1730fffbd1d25eb6cf54234 SHA-256: f37b1bbb997330f67226a32de178d3651494957594873a368b33052a971632a2
196 Risk Score

Malware Insights

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

This PDF document contains multiple links to external URLs, many hosted on compromised WordPress sites, suggesting a phishing or malware distribution attempt. The heuristic 'PDF_RANDOM_URL_LINK' and 'ML_NYX_PDF_MALICIOUS' indicate a high likelihood of malicious intent. The document body, though heavily obfuscated, contains text related to 'calculator critical value', likely a lure to encourage clicks on the embedded malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://crysiq.ru/uplcv?utm_term=f+calculator+critical+value PDF link annotation
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/obvido2man4uaccr9llj8a77q5/jububikiwuduxusurowod.pdfIn PDF document text
    • http://zetrade.cz/userfiles/file/muximatepilasawovulu.pdfIn PDF document text
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160909cfa767e0---fuzexevakupux.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075bd8c68e3a---sadoravagesuzobaven.pdfIn PDF document text
    • http://baschin-heizung.com/meineBilderAlbertGrundschule/file/19183687732.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606f436f7e216---81403977854.pdfIn PDF document text
    • https://birudongker.com/contents//files/gowutedegetafige.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606f93281eef8---51721411875.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607e1284d9e78---15875042873.pdfIn PDF document text
    • http://0vote.com/ckfinder/files/64266382197.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f5d5ea2fae---bodatusujetolemokexaji.pdfIn PDF document text
    • https://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/96512933786fe6e04644616a35a24cd1/fukexoruxugidigir.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160b7d49f7552e---xosobugogobanir.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0001270c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1270C 4628 bytes
SHA-256: 07189fe4da74c7ad06557dcb7855ba970c3921ac4a4cb1a1f18eb59ec2da0cfa
font_01_sfnt_off000136e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136E1 11368 bytes
SHA-256: ce573cb0945db5514b10605ed2ce4281653e9011e2481aee6218e48418f98eae