Malicious PDF — malware analysis report

Static analysis result for SHA-256 522b53d88a9d40b2…

MALICIOUS

PDF

86.2 KB Created: 2021-07-21 13:18:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 1a316c166d74584ead16e6df6d61cdc8 SHA-1: 761e35578a37246756595586c42efdeed98f4025 SHA-256: 522b53d88a9d40b25a1e8319510cb7b336df1388eb2e717c3dbb6ee55924249c
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains numerous links, many pointing to compromised WordPress upload directories and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of external URIs and the overall structure indicate an attempt to exploit users via malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://autothudo.vn/upload/fck/file/togowumigojak.pdf In PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a37dc88c60---89691550129.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c578891fa64---xatugin.pdfIn PDF document text
    • http://liubeauty.com/luutru/files/vavipowavux.pdfIn PDF document text
    • http://ranahytta.com/ckfinder/userfiles/files/gewigalovidedejezopir.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a3ef5770d1b---62352908263.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/xegukop.pdfIn PDF document text
    • http://architettoseneca.com/userfiles/files/fovurorekifuka.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/hf5had8cu7rv1b58fa0dd84sc8/ximuboxifan.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/79354841579.pdfIn PDF document text
    • http://bawaconstructions.com/editorData/file/govodekepanibixuguz.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/44a8fe3ea41a42b6f043d341f10d518e/28473038133.pdfIn PDF document text
    • http://sirmamedia.com/ckfinder/userfiles/files/84651977973.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2d982f1dc---56387404416.pdfIn PDF document text
    • http://rasciindia.com/firetech/ckupload/files/78408482774.pdfIn PDF document text
    • http://agendaalzheimer.org/files/galeria/files/22361520304.pdfIn PDF document text
    • http://wheatland1971.com/clients/25033/File/78301437483.pdfIn PDF document text
    • http://austria-ex.com/images/blog//file/69723083678.pdfIn PDF document text
    • http://metabolit-plus.ru/files/file/11046703717.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1b810c7cee---pemovu.pdfIn PDF document text
    • https://myphi.biz/nbloom/fckuploads/file/pozirifuwekiwalojo.pdfIn PDF document text
    • https://grand-forge.ru/wp-content/plugins/super-forms/uploads/php/files/e5dee419252a5051ecdc800ae743a9b8/rojilawalixukobe.pdfIn PDF document text
    • https://wccia-vastu.com/wp-content/plugins/super-forms/uploads/php/files/b1eb7951eebb7f4f2bfec99771b0d902/26510572201.pdfIn PDF document text
    • http://lhsclassof1971.com/clients/74120/File/87037974550.pdfIn PDF document text
    • https://juhaszautovill.hu/userfiles/file/73931418703.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=integers+and+exponentsPDF 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_off0000eb77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB77 10484 bytes
SHA-256: 90ac0ef4ca7e990e314d356902fc0965bce51935030cae6d2a427f0e340924f9
font_01_sfnt_off00010337.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10337 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011b49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B49 18072 bytes
SHA-256: bb04959e6a1fc9ffcbc77c362285944beb9a286d257d87e874b06c50f73a5726