Malicious PDF — malware analysis report

Static analysis result for SHA-256 604f31c4ee3612df…

MALICIOUS

PDF

84.1 KB Created: 2021-09-05 05:07:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 18cf4c111bba1bc4a46d5fcad04e43f0 SHA-1: 89a1e27b4021b3fe6e4a078c9e22ad4d9c70ed3f SHA-256: 604f31c4ee3612df6e4afc35edbcead34e93f1cbe8c6cc188b4b9b1741e7b006
156 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 for SEO manipulation or phishing. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and link farm behavior are consistent with techniques used to redirect users to malicious sites, likely for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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 http://cnc-soustruzeni.cz/files/file/27437914260.pdf In PDF document text
    • https://www.djluk.co.uk/wp-content/plugins/super-forms/uploads/php/files/gqpvqn8ti0aqhm7f9eadancsf1/28382039053.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/scvjpav6jlsue5l5gr2pvosebq/56203534768.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086932c3e591---12894143372.pdfIn PDF document text
    • http://studiodebiaggi.eu/userfiles/files/bawoferuworuxasafi.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/f7aefc3be72205e41a02d783ec693075/zosapiwaxuka.pdfIn PDF document text
    • http://yuha.be/_files/file/kijezugawumusun.pdfIn PDF document text
    • https://dodomacnosti.net/data/file/sazisuwozebolujulelume.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612357d9b83b6---48740064280.pdfIn PDF document text
    • http://ruilong-ironwork.com/CKEdit/upload/files/tabasaba.pdfIn PDF document text
    • http://airconbank.com/upload/fckeditor/file/gufesejivamiki.pdfIn PDF document text
    • http://gekon.net/userfiles/file/49973369973.pdfIn PDF document text
    • https://remoteyourstaff.com/calisma2/files/uploads/vativapedose.pdfIn PDF document text
    • https://vientangluc.com/upload/files/fibagotajidonikibumewirog.pdfIn PDF document text
    • https://www.hausbootgeiseltalsee.de/wp-content/plugins/super-forms/uploads/php/files/efjaehhmvl3cs3esk3rsdbvbsb/62801441248.pdfIn PDF document text
    • http://luchetti.it/userfiles/files/69109724672.pdfIn PDF document text
    • http://autoklej.pl/app/webroot/media/files/84903664608.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/55f8287b718c434b6b1149e916f4ecf8/53472840094.pdfIn PDF document text
    • http://nickels.design/ckfinder/userfiles/files/11437734936.pdfIn PDF document text
    • https://www.indoorclub-informa.com/boletines/img/file/jonit.pdfIn PDF document text
    • http://rexant.by/upload/editor/files/79759374919.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/raf6mk3o5afrl49au891flmh8r/tibigepurarufudo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=calcul+puissance+radiateur+chauffage+central+pdfPDF 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_off0000de68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE68 20496 bytes
SHA-256: 2e911b5c23d83e643b65bbd2f439147400ad7eb00b18f3511e1aa171b006203d
font_01_sfnt_off00011170.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11170 10912 bytes
SHA-256: 572646ff9ba8492044886743a25c372645cf7ec8326ae7819d0104479135a742
font_02_sfnt_off00012a6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A6F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1