Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf33a538b803bcb2…

MALICIOUS

PDF

98.0 KB Created: 2021-08-14 02:27:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: e4246f34c064b6884a7f734bb26b44d9 SHA-1: ea1ca8a19b16ccc2913cd92254df4d3e47f79d69 SHA-256: bf33a538b803bcb28a6c946766603ff46135f0a2ad4ee024383794a429c50ae9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged by multiple heuristics and an ML classifier as malicious, specifically identified as a phishing trojan by ClamAV. It contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting an attempt to distribute malicious content or phish users. While no scripts were directly extracted, the presence of numerous external links indicates a likely attempt to redirect users to malicious sites, potentially for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/sromf54bja06i9b9i54a71bp84/31998371465.pdf In PDF document text
    • http://csc0851.com/userfiles/file/20210623043634_vodlhg.pdfIn PDF document text
    • https://yukkumpulgroup1.com/contents//files/riselusi.pdfIn PDF document text
    • http://teplospectr.ru/images/files/33089898581.pdfIn PDF document text
    • https://hasekei.jp/userfiles/file/61644532067.pdfIn PDF document text
    • http://kapsalonvogue.nl/files/file/49266955127.pdfIn PDF document text
    • https://pergamine.com/ckfinder/userfiles/files/33802766999.pdfIn PDF document text
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/manskegptrr4aduk3dukufvk1v/dokupefevuxugosonaletomo.pdfIn PDF document text
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/upt4oe52neq5lccvtoeudqpbni/kerevedokupewidulevika.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087ddb8bfeea---88596380282.pdfIn PDF document text
    • http://pincesorvarshop.hu/editor_up/23903741850.pdfIn PDF document text
    • https://areicon.com/images/file/99417680682.pdfIn PDF document text
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/7rqo1h7470qpq0bd82vhdfnut3/11597439090.pdfIn PDF document text
    • http://turar-mussin.com/userfiles/File/ribibonenu.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca3ddacc4b3---fipusarakavalemevi.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c0775d40de2---58202515037.pdfIn PDF document text
    • http://investin-khj.ir/ckfinder/userfiles/files/daleluwi.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160f7613e07bb8---jurijawi.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1610660f0043d5---35269983273.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a11aac7cf0f---zobarovasozipomilofifezim.pdfIn PDF document text
    • http://auto4-spb.ru/public/images/ckfinder/files/38924877037.pdfIn PDF document text
    • http://drive4smilesquebec.ca/clients/f/f5/f58105ca183540932673f5bf18e62671/File/kofuxakadewikagikili.pdfIn PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/7m769d5jc502225b1v1fbo8nr4/poniwuxo.pdfIn PDF document text
    • http://hrt-foto.hu/_user/file/70799388907.pdfIn PDF document text
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b45f79b47c7---xidajutuwulasetobeb.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=thomas+calculus+13th+edition+instructor+solutions+manualPDF 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_off00010f94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F94 21536 bytes
SHA-256: 12275d2cad75ec83ee89214d982cdccf921ad4a1c137fb00f2f11fae49a04224
font_01_sfnt_off00014680.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14680 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015e97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15E97 10920 bytes
SHA-256: cdce6bf5e8dd577516c2d9b53f42f0159d139e59bc7035315bd9a4ef55d89992