Malicious PDF — malware analysis report

Static analysis result for SHA-256 851c3c12167aeaf9…

MALICIOUS

PDF

70.5 KB Created: 2021-10-03 19:32:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: fbdcad7049012159d43804f2cfe072b1 SHA-1: 88b5c54a8f249b5769b94266647238885ded4fae SHA-256: 851c3c12167aeaf9859e65658b1ddfc0910bcd11dc130cc060a76e7a71dd4abb
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics indicate the presence of a link farm pointing to compromised CMS upload storage and disposable hosting, suggesting a phishing or malware distribution lure. The document body is heavily obfuscated, preventing a clear understanding of its specific content, but the overall structure and URL analysis point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://temdientu.vn/images/ckeditor/files/gamezapatunuxosazesiv.pdf In PDF document text
    • http://adacu.org/userfiles/file/20210929112650.pdfIn PDF document text
    • http://bulgankhangai.mn/userfiles/files/64198750687.pdfIn PDF document text
    • http://xn--80aafkqcanfpgnhbng3b5i9a.xn--p1ai/pict/file/wiguk.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/8ba99ac07784fec5996740775fcf2b35/90080657018.pdfIn PDF document text
    • http://scherzerpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sorotinuvaw.pdfIn PDF document text
    • https://www.jancsoalapitvany.hu/ckfinder/userfiles/files/57646652025.pdfIn PDF document text
    • https://aksukartela.com/images_upload/files/31965172331.pdfIn PDF document text
    • http://brilsports.ro/userfiles/file///68378530944.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134db85b0159---xisajenijuxex.pdfIn PDF document text
    • https://satesayap.com/contents/files/rezixebapusituzavuda.pdfIn PDF document text
    • http://maradonasalud.com.ar/ckeditor/ckfinder/userfiles/files/80801596550.pdfIn PDF document text
    • https://polenhosting.com/calisma2/files/uploads/96853540097.pdfIn PDF document text
    • http://e-motyle.natura2000.pl/imgturysta/files/ruruz.pdfIn PDF document text
    • http://longtra.vn/userfiles/file/29400454119.pdfIn PDF document text
    • https://tanvietnamdinh.com/uploads/files/78768298493.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614064a89e76c---debisib.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614dd7decdfe4---paxolanimeroju.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143e731a2f64---66431706883.pdfIn PDF document text
    • http://dostavka.markasib.ru/ckfinder/userfiles/files/11907281400.pdfIn PDF document text
    • https://namkhoasaigon.vn/web/images/files/kagovo.pdfIn PDF document text
    • http://laptopplus.be/app/webroot/files/userfiles/files/35059384864.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/wixiwutozilotukijipozukim.pdfIn PDF document text
    • http://cloverdiamond.com/file/63975506521.pdfIn PDF document text
    • http://schokofontaene.de/idata/sadexufiwisopodeve.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613610c7c2870---11280764558.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=baaghi+3+movie+download+filmywapPDF 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_off0000b55e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB55E 14816 bytes
SHA-256: 6188bfb0a8de4def513a4f7b9935e248fc09366770f8ef00ef7ea6a385415725
font_01_sfnt_off0000daab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAAB 11068 bytes
SHA-256: 58f40c7f11ea7cc32b44245a8a7442fa305f5296544b878987e7f362973d40ff
font_02_sfnt_off0000f423.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF423 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1