Malicious PDF — malware analysis report

Static analysis result for SHA-256 16d78a93a3d8aa54…

MALICIOUS

PDF

70.9 KB Created: 2021-09-17 21:55:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 411f8920930f7f660e40a6b18bf0d6ce SHA-1: 25fcb8df3a9cd767b02ee2947151a18addcb5445 SHA-256: 16d78a93a3d8aa54899d717e3b2c4f46356e5a602289049ad4fcd38d479a9206
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially compromised websites or disposable hosting. The primary purpose appears to be directing users to external sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://mayepnuocmia.vn/data/ckfinder/files/53917325100.pdf In PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613484eaded66---dutawixefitezesadot.pdfIn PDF document text
    • https://aymsoft.us/aym_image/files/kalunibinaserudifab.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/lpdhp1mvcn9c3prcj9um3hdmf8/rigagod.pdfIn PDF document text
    • http://prunay-en-yvelines.fr/ckfinder/userfiles/files/patagekubenudidux.pdfIn PDF document text
    • http://ogledalata.bg/uploads/pages/files/nadukeziwor.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/4uuc065phbeorf6brphekp7338/80288392522.pdfIn PDF document text
    • http://detikakdeti.ru/img/file/luxuw.pdfIn PDF document text
    • http://edilcfcostruzioni.com/userfiles/files/zifanulusokilevutodobajax.pdfIn PDF document text
    • http://tostonet.cl/ckfinder/userfiles/files/wifite.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/orovew.pdfIn PDF document text
    • https://ruiguoex.com/upfile/files/2021/09/14/jewijugibezixagamos.pdfIn PDF document text
    • http://topimmigrationlawyer.org/ckfinder/userfiles/files/zudipa.pdfIn PDF document text
    • http://www.taimaobi.com/admin/ckfinder/userfiles/files/vutawajawewizavuzi.pdfIn PDF document text
    • http://creationart.hu/files/file/57892077795.pdfIn PDF document text
    • http://jsjxh.org/filespath/files/20210906125553.pdfIn PDF document text
    • http://0975811252cool.linker.tw/files/popimibadinirimisalesug.pdfIn PDF document text
    • http://falerisztika.hu/tmp/88794645435.pdfIn PDF document text
    • https://thehouseproduction.net/file/98850530275.pdfIn PDF document text
    • https://glearningsolutions.com/userfiles/files/9459895604.pdfIn PDF document text
    • http://manu-transport.com/documents/file/tojolid.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/c0494b0804992702e744eda33fabf78f/debibiwegufulisemibap.pdfIn PDF document text
    • http://rfinshaat.az/userfiles/file/raxovugodesiwadalururowo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=friv+ghost+riderPDF 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_off0000b3f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3F9 16424 bytes
SHA-256: 4af63ef98ff6d41a157126a25d2f2896288de4a792a1e6ee128baf182047dfaa
font_01_sfnt_off0000de09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE09 10256 bytes
SHA-256: d139560922a0329f9783c400f64fa6c61a68efcda58c1765a1ce729efd83aef6
font_02_sfnt_off0000f505.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF505 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1