Malicious PDF — malware analysis report

Static analysis result for SHA-256 837c432a7e97b902…

MALICIOUS

PDF

78.2 KB Created: 2021-09-19 13:05:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 5d2043c5f9797c0219908d254d550a47 SHA-1: 71e92be7f02cf269e84f3c1620d86c0faaf51cab SHA-256: 837c432a7e97b9023d145242d018cf378c483a197fa5c9b719d6c41e2ee9f2ee
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS uploads, indicating a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://graczeonline.pl/userfiles/file/7405941743.pdf In PDF document text
    • http://logistra.fr/ressource/site-image/files/zejise.pdfIn PDF document text
    • http://istanbulballoons.com/ckfinder/userfiles/files/71584061472.pdfIn PDF document text
    • http://sabancilojistik.com/userfiles/file/39824538159.pdfIn PDF document text
    • https://bahceneryaman.net/public/content-images/files/votunisaxakevakeg.pdfIn PDF document text
    • https://losaltos.com/wysiwygfiles/file/fafagabagox.pdfIn PDF document text
    • http://serbanindustrialconstruct.ro/uploads/files/23572779408.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613af90084bbf---sanopevef.pdfIn PDF document text
    • http://alltimescare.com/attachment/files/58599561205.pdfIn PDF document text
    • https://weishinclinic.com/uploads/files/202109021150273928.pdfIn PDF document text
    • http://oishisushigd.com/uploads/files/89691123898.pdfIn PDF document text
    • http://rubella2.integra-sh.com/userfiles/file/furadepojem.pdfIn PDF document text
    • http://greece-ex.com/images/blog/file/wofuwexabamadiviji.pdfIn PDF document text
    • https://profesa.net/userFilesfile/72929718176.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161317eecf347b---10507124046.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/3c2e165a46cf0162c67ac2154ce9eec8/87665905725.pdfIn PDF document text
    • https://kurashi-kyoiku.com/cms/dat/upimg/file/zugagukuzugilagoru.pdfIn PDF document text
    • http://idcla.net/upload/files/5033817616.pdfIn PDF document text
    • http://bsp-plovdiv.org/ckfinder/userfiles/files/95673000852.pdfIn PDF document text
    • http://www.musicboxpiano.com/contentfiles/31898868641.pdfIn PDF document text
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.net/ckfinder/userfiles/files/vonujanepomodonopojot.pdfIn PDF document text
    • https://buonoantonio.it/userfiles/file/75389902214.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=dbz+mugen+android+downloadPDF 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_off0000cd61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD61 10712 bytes
SHA-256: f5e75c92fe241d54b28a54f1dd5891315c555e1b563d5f5db5edc525d22d07de
font_01_sfnt_off0000e5c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C1 17396 bytes
SHA-256: 167c6e0f0f093bc76901569b1fc776d73ea1ed4268e967e9c959be497ccc49a0
font_02_sfnt_off0001131f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1131F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1