Malicious PDF — malware analysis report

Static analysis result for SHA-256 68e771658042cde1…

MALICIOUS

PDF

82.0 KB Created: 2021-09-05 10:02:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: be0d3f33a3890b50c9f2f60f93243673 SHA-1: 3fe50ba5c23f6521e5d83c157b5670b1b238cd9e SHA-256: 68e771658042cde1b679227ef6cf18df11c531e09d5d01072238e32575bc242b
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. It contains numerous links, many pointing to compromised WordPress upload directories and other disposable hosting, suggesting a link farm designed to manipulate search engine results or direct users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://e-uchebnici.com/img/file/4408288255.pdf In PDF document text
    • http://baocaosuhoatoc.com/luutru/files/23197137340.pdfIn PDF document text
    • https://www.electriclighting.com/wp-content/plugins/super-forms/uploads/php/files/ce7a37e1b853a228b19c14f8450bb25f/lenaxiwibaroxobetekoso.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/wozozelibipawulusutegerof.pdfIn PDF document text
    • http://big-blue-bus.com/pics/fotos/1/file/rebuditafesenedevebawa.pdfIn PDF document text
    • http://dunakeszi.varosom.hu/userfiles/files/27589259519.pdfIn PDF document text
    • http://abpaluso.com/upload/file/rofagetajevo.pdfIn PDF document text
    • http://patriabrno.cz/userfiles/files/69383878935.pdfIn PDF document text
    • http://retco.ge/ckfinder/userfiles/files/28383403836.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/aa72669a571164e6f45708e3bec24d28/26106695734.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a1d3b0369eb---31905175664.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/40b2087393852bc24fd9f620ef43a222/42471195570.pdfIn PDF document text
    • http://xn--xhq021fvrwdth.com/d/files/dobuvejawo.pdfIn PDF document text
    • http://megaeventoa100.com/clients/f/fa/fa03970f5feff24be7017758158681b9/File/wivofapomijazi.pdfIn PDF document text
    • http://aps-mes.com/files/file/5355152775.pdfIn PDF document text
    • https://leuphuotcamap.com/uploads/image/files/goxenanidinoxidusomejaz.pdfIn PDF document text
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/fftj676su06so4nbsvm7e7i4sm/xefixotezedobilupesinus.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2188d5817---noseki.pdfIn PDF document text
    • https://chulintemple.house-well.com/CKEdit/upload/files/24374637077.pdfIn PDF document text
    • https://vresponse.net/userfiles/file/lavinowudezevi.pdfIn PDF document text
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f24560b540a---22898055795.pdfIn PDF document text
    • https://bitree.ru/ckfinder/userfiles/files/73321319043.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160f4a7878a0e3---57616531564.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=sulfato+de+zinco+bula+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_off0000d871.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD871 18956 bytes
SHA-256: 791673d0300e89b1083809ee8637e222b88ead7e57951f13fc6c7773d7ed963d
font_01_sfnt_off00010a02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A02 10720 bytes
SHA-256: b05909a0a27844f0def1e26cef1746b54cf2c6ea0230746dab0f252017895233
font_02_sfnt_off0001228e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1228E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1