Malicious PDF — malware analysis report

Static analysis result for SHA-256 de13dc72aa7484b6…

MALICIOUS

PDF

84.2 KB Created: 2021-06-28 16:46:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 72a21005c27b526f5f5692d126597085 SHA-1: 1cc1e1e30b2a7597e97c00d2c6964a339b6bc7ee SHA-256: de13dc72aa7484b6eea01668094cc7138f7d5ec85eb58919e17d5eaf3306db2a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is often used to execute malicious actions. It also features a link farm pointing to numerous external websites, many hosted on compromised WordPress sites, suggesting an attempt to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://istanbulbalbir.com/upload/ckfinder/files/99532319285.pdf In PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/goo2m403m6c80h369u73el3mn0/dulezinov.pdfIn PDF document text
    • https://baongochoa.com/upload/file/23757498144.pdfIn PDF document text
    • https://dm288.rs/slicice/file/78409755383.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16084d5661fa3d---sinukanidofikugijigogoxer.pdfIn PDF document text
    • https://itchanoi.vn/uploads/news_file/mukun.pdfIn PDF document text
    • http://cablexconsulting.com/Upload/file/34980078050.pdfIn PDF document text
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/5fd6191614d52671d33cd114f5d208fb/sunofu.pdfIn PDF document text
    • http://andrelandberg.com/userfiles/file/22705168647.pdfIn PDF document text
    • http://grandbarnettfamily.com/clients/a/a0/a01b80d98e57c38af56892ab55e7d82f/File/12178705499.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/0babb9oj35r0anh80pks609udb/gogatizafibibulejin.pdfIn PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/acf2b1ec88efa470dcca9504faaa9981/bubedodizagedexa.pdfIn PDF document text
    • https://www.llgnjinc.com/wp-content/plugins/super-forms/uploads/php/files/e18df772f21ba52f0ad54a219acf891e/52109079538.pdfIn PDF document text
    • http://volvo-cars.jp/js/upload/files/87429624533.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/n1qa98oruggebei5qot830mjds/bupirubemoporegelisasufed.pdfIn PDF document text
    • https://a2designbg.com/userfiles/file/87044062193.pdfIn PDF document text
    • https://beautyyaurient.com/editor_upload/file/28559871160.pdfIn PDF document text
    • http://drairtools.com/ckfinder/userfiles/files/zukolit.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1609ec70c2dc88---gulojerixemifo.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4c08ec6507---2518006207.pdfIn PDF document text
    • https://cor.org.ar/wp-content/plugins/super-forms/uploads/php/files/t4ao52ku730j7v1vin5rjddvo3/41121371146.pdfIn PDF document text
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/182spvcps3vt4hf1lsahsm51h5/tidizokugafewu.pdfIn PDF document text
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160736f18eab4d---mewezexizabixofizibepepab.pdfIn PDF document text
    • http://www.multigacos.com/admin/uploaded/fck/file/bizanuwujodipodajo.pdfIn PDF document text
    • https://fasaac.org/temp//files/newavurenov.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/dbede5777ffc6827c0b0692e9af8473a/34968602851.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=swelling+on+outside+of+kneePDF 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_off0000e5a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5A7 10620 bytes
SHA-256: 3f2f037c38e9310361d27110812e7129a27a4cacf832bdd06315a02ea2ba3891
font_01_sfnt_off0000fde8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDE8 17396 bytes
SHA-256: 307ef11c5b1d4d9849441151248b52de91855b58c195ee82326831669e7fba32
font_02_sfnt_off00012b3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B3F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1