Malicious PDF — malware analysis report

Static analysis result for SHA-256 df621d41343ebc6b…

MALICIOUS

PDF

82.7 KB Created: 2021-06-24 15:44:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 4767eeaecf0d28aeec28babf7ae09e3c SHA-1: 2b91bcdc5c680d15c8191cd7f66103715234f92e SHA-256: df621d41343ebc6b51a6bcf80f1d38adb0d0d7350f1834d25402c0209eaaf86b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains, suggesting a link farm or phishing lure. The document body, though heavily obfuscated, contains references to 'Codycross group 52 puzzle 4', indicating a social engineering pretext to entice users to click on the embedded malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://synerhu.ru/uplcv?utm_term=codycross+group+52+puzzle+4 PDF link annotation
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9090507b8---91303450719.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/jemipimamunibeges.pdfIn PDF document text
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/e1c6cd7af18c5b7981b4f7e2bc50788b/32091127049.pdfIn PDF document text
    • https://endoaccessories.com/wp-content/plugins/super-forms/uploads/php/files/f226v72tig1lrb4odc0av70fvf/wufoguwusorafu.pdfIn PDF document text
    • http://bestapp4u.com/admin/uploadedfiles/file/rizubukidutepenexivote.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16073851f3198b---1771215418.pdfIn PDF document text
    • http://malagi.pl/user-files/fck/file/lipomoremuvigagoz.pdfIn PDF document text
    • http://ehomeforeclosure.org/images/file/xurixa.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/tavudivij.pdfIn PDF document text
    • http://photographybynami.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b2ae468471---1604237777.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/a13hc9uvdalmeb4cnclqtuobg2/10500251521.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a580c9e625---wagebemenudukato.pdfIn PDF document text
    • http://altelaw.com/uploads/image/file/82115266501.pdfIn PDF document text
    • https://cal.lighting/wp-content/plugins/super-forms/uploads/php/files/4cf5c30063f3594a0c52db3735d2d278/jokadowiturafenuvorejode.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c59f20fcce---12120939389.pdfIn PDF document text
    • 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://scripts.sil.org/OFLIn 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_off0000ef0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF0A 5432 bytes
SHA-256: 7db7764c9d395e38a77af2cffb5cf6dbd3a04b8a6cfb4dd6d7230bc485ba914b
font_01_sfnt_off000101b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101B3 11428 bytes
SHA-256: a27ad466a87f646c3ba258e9f9aed1d023feae3115d2b43042862e1e05717d9a
font_02_sfnt_off0001283e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1283E 16204 bytes
SHA-256: 541fa2b6826b0add99b7d5a173ef1e6a5567607b5192f75b810eb17d6a563501