Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca7881a4ec95dca2…

MALICIOUS

PDF

82.6 KB Created: 2021-09-02 17:02:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a04d07f53e1f153dc6b813770f7b613a SHA-1: 72b44d656a4353bfc241e9eff9b177505138ab3d SHA-256: ca7881a4ec95dca2ad712bff31d68fdfb5571554e3ae897e79a82200828c4275
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9762

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://wastran.ru/uplcv?utm_term=a+handbook+on+torsional+vibration+pdf+download PDF link annotation
    • http://vertracapital.com/uploads/files/53142010420.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080c7dd060d1.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/546b357331562e78ecc7b4a108745816/65608075668.pdfIn PDF document text
    • http://mobilesamara.com/img/files/file/59432915726.pdfIn PDF document text
    • http://thayloilocnuoctaihanoi.net/upload/files/11084188864.pdfIn PDF document text
    • http://ambulatorioveterinarioilghirlandaio.it/userfiles/files/pegizaja.pdfIn PDF document text
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/18da7073f0446c78703bb76852a9c46f/92868168913.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ae351027d82---68729722990.pdfIn PDF document text
    • http://scuderieverdina.it/scuderia/userfiles/file/55869796274.pdfIn PDF document text
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/3li7dp747n00kbl8k24djo8a8k/30117108153.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d0359d667e4---vatitokog.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/160edd18a5a504---7313224656.pdfIn PDF document text
    • http://iccj.jp/images/uploads/fckeditor/file/livewivesasawavaxexezano.pdfIn PDF document text
    • http://mywayrtk.info/userfiles/file/17874555593.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf98138116---54980970349.pdfIn PDF document text
    • https://slide-bearing.com/d/files/78260288599.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b668d3ed9e8---rudobuwezipepaxutidubisu.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/ffb0cd88ad8be2967f5da7c4fe2b25ac/25832683499.pdfIn PDF document text
    • http://uptownherndon.com/uploads/files/85851990762.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160985af556e69---rezegixufalisase.pdfIn PDF document text
    • http://ardechetendancebrut.fr/userfiles/ardechetendancebrut.fr/file/63841882113.pdfIn PDF document text
    • http://www.assignproject.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607075d24d69f---maliretedepegukifomisoz.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070139f33037---3317372634.pdfIn PDF document text
    • http://notariocprietoa.com/notaria/documentos/files/82369475014.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1608f4030bb923---pebumagekapoputikaj.pdfIn PDF document text
    • http://bright-mineral.com/uploadfile/file/2021052115535367.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/16102d06bdc7ee---lufaruda.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off0000dc1a.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0xDC1A 18716 bytes
SHA-256: fdec17ce4e752200b6fcc42cb6783891c550e6608a7a612314217b2e327e8005
font_00_sfnt_off0000c409.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC409 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fac5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAC5 15628 bytes
SHA-256: 785af8212e6fda49f7e467e504dd3c8b6dd9da7be474edc30edd8dd8d6588c5c
font_03_sfnt_off00012296.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12296 10828 bytes
SHA-256: 5e0bbb86a1c8eb26c274afc1c1e1e0e9ec837c576315ae7f2bf7ce0db425c7a2