Malicious PDF — malware analysis report

Static analysis result for SHA-256 d56505098c6b6e50…

MALICIOUS

PDF

84.5 KB Created: 2021-07-24 19:02:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: c1f7991fc6800d680f527af2745cb9ff SHA-1: ecec53b7aac34f46a2e4478115df32e4ada47970 SHA-256: d56505098c6b6e50fb349424e745a2571337088bdb474b06711cb0abaefd6b74
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to compromised CMS upload directories, suggesting it's part of a link farm or SEO manipulation scheme. ClamAV detected it as a phishing trojan, and ML classifiers also flagged it as malicious. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the presence of external links and the detection results strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://keyflounge.nl/userfiles/file/85132928198.pdf In PDF document text
    • https://charlesstreetvideo.com/userfiles/file/xuper.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/47870172994.pdfIn PDF document text
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c1dc22c930---nakipemunu.pdfIn PDF document text
    • https://gearforfree.com/wp-content/plugins/super-forms/uploads/php/files/2m5gflplslbjqildc31qrmsn20/20622839427.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077941a33184---77337565699.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/felekik.pdfIn PDF document text
    • http://ajivikafinance.com/userfiles/file/xobubugadalezitesonipovi.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/160a03ae908791---vizuxiburodizax.pdfIn PDF document text
    • https://karinbentum.nl/uploads/file/49154713078.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb29728e6e8---zodijegewa.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/aa69e1da36c4936dccb59bf768c28ad3/rowevekegenefevuwusif.pdfIn PDF document text
    • http://henri-ruch.ch/doc_pub/file/zifebanitokureg.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad9d21033df---38053081857.pdfIn PDF document text
    • https://dienlanhhonganh.com/images/pic/file/11494012525.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd3a3add86---33814582358.pdfIn PDF document text
    • http://homeopathyhongkong.cn/files/10296369501.pdfIn PDF document text
    • https://rivieresoceanie.com/ckfinder/userfiles/files/jutorerepajaxalu.pdfIn PDF document text
    • https://bselink.com/userfiles/file/4291566310.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/e0983565144a611a961e8e40c55fb243/nisinitovejeviporumola.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd798d5e22b---12412628506.pdfIn PDF document text
    • http://roanfamily.net/clients/0/01/01b24a6c100194bbc8678883f3cd4a53/File/39419968700.pdfIn PDF document text
    • https://chokysitohang.com/Uploads/userfiles/files/jubiteliriduje.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073118f62e2e---xokokomuwetagasugawigoxa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=solving+exponential+functions+worksheet+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_off0000e2cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2CC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fade.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFADE 17760 bytes
SHA-256: 4714d6c4c90e1dcd12ff4de450accbcd526ff24bade7b444785eed32deb8e937
font_02_sfnt_off000129ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129CE 11420 bytes
SHA-256: 393d095055020fe4b4c8e7463f904435c4ee1a09226fa47a95af078d38062a1b