Malicious PDF — malware analysis report

Static analysis result for SHA-256 a665f705e2df7c0f…

MALICIOUS

PDF

81.8 KB Created: 2021-09-24 10:14:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f6aefd78caa0797bd228799f38ffa22c SHA-1: 6b6e11309e1b0e2135d298bd2cdcc368c22322ec SHA-256: a665f705e2df7c0f86e869e33a5e58a5415c83369cbbf51e3c7553c216816a6f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is a PDF identified as malicious by ClamAV and an ML classifier. Static analysis revealed it functions as a link farm, with numerous embedded URLs pointing to compromised or disposable hosting domains. The presence of multiple external URIs and link farm heuristics strongly suggests an intent to redirect users, potentially for phishing or SEO spam.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://binarbaidtrading.com/public_html/userfiles/file/40544831105.pdf In PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614555dbc6efc---kekaluguzo.pdfIn PDF document text
    • https://bdata.vn/upload/files/5647440863.pdfIn PDF document text
    • https://www.wappa.com.au/siteadmin/ckfinder/userfiles/files/8839808020.pdfIn PDF document text
    • https://inunekocp.jp/mailmagazine/upload/files/fikaw.pdfIn PDF document text
    • https://bevasilicones.in/userfiles/file/vibiliz.pdfIn PDF document text
    • http://yournamebadges.com/withyourdog/cms_uploads/file/xetalagolewararado.pdfIn PDF document text
    • http://lnimeina.it/userfiles/files/41385012757.pdfIn PDF document text
    • http://cu-hinothai.com/ckfinder/userfiles/files/bavaxegabepevoroxorawoz.pdfIn PDF document text
    • https://sakkestadbil.no/userfiles/file/newerikolofiloloresi.pdfIn PDF document text
    • http://traktor-tv.de/sites/default/files/file/seguxuti.pdfIn PDF document text
    • https://dotcomtravelegypt.com/userfiles/files/37625710754.pdfIn PDF document text
    • http://n3ss.ro/ckfinder/userfiles/files/bevuje.pdfIn PDF document text
    • http://caerulumpharma.com/upload/files/xovatisovagirik.pdfIn PDF document text
    • https://profipreklady.cz/www/ckfinder/userfiles/files/17558847702.pdfIn PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/ac8774781252c885c4e66efca769ad18/51492135230.pdfIn PDF document text
    • https://studiecarriere.it/uploads/file/16702186158.pdfIn PDF document text
    • http://luisacortesearchitetto.it/userfiles/files/31066161831.pdfIn PDF document text
    • http://ttc-investco.com/img/files/59148963157.pdfIn PDF document text
    • http://antwerp-reefer-tournament.be/argt/files/sekumenuvorodixikuvar.pdfIn PDF document text
    • http://buzmakov-ua.ru/admin/ckfinder/userfiles/files/liviwavejukesor.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/po8pdjpo86djr2cr3uu3c62n7c/70083943104.pdfIn PDF document text
    • http://0575zl.com/userfiles/file/sifimifudoneleduted.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=gambar+untuk+wallpaper+androidPDF 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_off0000db18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB18 17704 bytes
SHA-256: d894c104afbcac6cfc73b14c2385a3e8025e78e42fbd8d617160e3a57e969c38
font_01_sfnt_off00010932.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10932 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012149.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12149 10844 bytes
SHA-256: 17505625e41fc86745873d7c82c0588ce42ce57a04f5087be1442c2d63110565