Malicious PDF — malware analysis report

Static analysis result for SHA-256 e638b41fc53dbcac…

MALICIOUS

PDF

86.2 KB Created: 2021-09-13 20:21:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 7f40bb319e4095d99712a5dc774c1ce5 SHA-1: eb55eb47ae3b8c14bbddf533b11af606dccef988 SHA-256: e638b41fc53dbcac52c6d5d1c5898243dda3766279fa162402cd83a5dc8952bc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was identified as malicious by ClamAV and an ML classifier. It functions as a link farm, with numerous embedded URLs pointing to various external sites. Notably, some of these URLs lead to compromised WordPress upload directories, suggesting a tactic to host malicious content or redirect users to phishing sites. The presence of a link farm and compromised hosting indicates an attempt to distribute malicious content or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://mkserwis.pl/userfiles/file/30015160224.pdf In PDF document text
    • https://www.auto-ecole-rive-droite.fr/ckfinder/userfiles/files/8601479746.pdfIn PDF document text
    • http://www.culturehousesun.org/photos/file/gowotafadapomevusedotipor.pdfIn PDF document text
    • https://aimtronu.org/userfiles/file/99718249128.pdfIn PDF document text
    • http://frankifoto.com/uploads/pages/files/28663820421.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/lleoagobchcd3adi9m4jmqfbbl/todedajosekutidad.pdfIn PDF document text
    • http://fipjp.com/userfiles/file/gumutoxifixuxopegozesasuv.pdfIn PDF document text
    • http://jamxmpharmatech.com/upload/files/fowoxepofopugisup.pdfIn PDF document text
    • http://www.pranabkumar.com/fckimages/file/24782931600.pdfIn PDF document text
    • http://vdadanang.vn/app/webroot/assets/files/38675925905.pdfIn PDF document text
    • https://bccphil.paramedix.biz/uploadfiles/file/32232819357.pdfIn PDF document text
    • http://www.hgbehringer.de/img/files/files/23337967034.pdfIn PDF document text
    • http://hzaidele.com/images/upload/File/36296575624.pdfIn PDF document text
    • https://chilegastronomia.cl/uploads/userfiles/files/viduliwofemu.pdfIn PDF document text
    • https://privatecambodiatour.com/userfiles/file/vuronaw.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134092386fd0---vokuteki.pdfIn PDF document text
    • https://lazdynumokykla.lt/userfiles/file/69857688454.pdfIn PDF document text
    • http://phunggia.biz/userfiles/file/60192204174.pdfIn PDF document text
    • http://dmhu.eu/uploads/uplib/file/buluziwedizogige.pdfIn PDF document text
    • http://thuaphatlaihanoi.net/uploads/files/tufupuf.pdfIn PDF document text
    • http://licausi.it/userfiles/files/95912659361.pdfIn PDF document text
    • http://crabandclaw.com/uploads/files/palapademusogezotawakej.pdfIn PDF document text
    • https://hotlinepro.in/admin/userfiles/file/69211488959.pdfIn PDF document text
    • http://bhavalaya.org/ckfinder/userfiles/files/12180643487.pdfIn PDF document text
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/vrvmao5o5tfslp8o81tdq53213/19292050830.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=what+apps+are+supported+by+android+autoPDF 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_off0000ecd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECD9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000104f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104F0 10788 bytes
SHA-256: d065558e6ad2ff3705b3a440f14624429f1896badbb1dd64c6ed918c9f0a8023
font_02_sfnt_off00011d8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D8E 17644 bytes
SHA-256: 6aa6cf4eeeb27acea2aa12fe7f5612c3866e4615d440846f21bd633e4e28207e