Malicious PDF — malware analysis report

Static analysis result for SHA-256 658d774b85dde88c…

MALICIOUS

PDF

88.4 KB Created: 2021-09-10 13:35:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ec4d5c3dc86548b2fb8b1c2fad9c6d1d SHA-1: a2a18b10a9e00ba52c0d7e5bf812ff154fc91641 SHA-256: 658d774b85dde88cdca058679f0e6d9798c5327de85a09aedabbe217ee5b9747
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of external URIs and link farm heuristics strongly indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://synerhu.ru/uplcv?utm_term=shooting+games+for+iphone PDF link annotation
    • http://xn--djr00fsyfv0o5qgy9u.net/filespath/files/20210903075711.pdfIn PDF document text
    • http://vtvxm.vn/userfiles/file/xazupefab.pdfIn PDF document text
    • http://www.huntsvillepr.com/files/files/76449294225.pdfIn PDF document text
    • http://russia-ex.com/images/blog/file/kabisabedaxukozumeji.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613302726ed01---xakusawezamakuluxisepit.pdfIn PDF document text
    • https://happycolaborativo.com/uploads/files/zenixapelelose.pdfIn PDF document text
    • https://g4m3s-4p1-12s1.com/contents/files/80744190100.pdfIn PDF document text
    • https://garraldaarquitectura.com/garralda_userfiles/files/dolisulupofokoto.pdfIn PDF document text
    • http://vcelari.naceradec.cz/includes/ckfinder/userfiles/files/42463463465.pdfIn PDF document text
    • http://gibisch.com/files/files/13894640942.pdfIn PDF document text
    • http://nhasachthunam.com/upload/files/91056178309.pdfIn PDF document text
    • http://chipgene.com/image/files/20210909_095222.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/39a3583c82711e71c94d61e25b885cd7/79506376205.pdfIn PDF document text
    • https://likeevent.it/writable/public/userfiles/file/xolopi.pdfIn PDF document text
    • https://gbp.dropship-online.com/userfiles/files/vuwamigoza.pdfIn PDF document text
    • http://electrogalicia.com/electrogalicia/recursos/archivos/97636944390.pdfIn PDF document text
    • https://nibrasimansch.com/userfiles/files/busolosutipabe.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133f1e82416a---begixejisamobi.pdfIn PDF document text
    • https://remont-bez-zabot.ru/files/file/53430102050.pdfIn PDF document text
    • http://easyliveconstruction.com/ci/userfiles/files/46482742170.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/40678735236.pdfIn PDF document text
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/161344e8e69fba---94159623859.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f59e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF59E 17784 bytes
SHA-256: 338f44a4bc734f289d10017d01cd106109744d5e932221a7e74ac300f9591df5
font_01_sfnt_off00012343.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12343 10836 bytes
SHA-256: e61e6ad3ea31740647dc9e4f13a2d919c2a2b0752a2c8d15725aa04afeac8312
font_02_sfnt_off00013c1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C1B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1