Malicious PDF — malware analysis report

Static analysis result for SHA-256 19cd54387f9957a1…

MALICIOUS

PDF

78.5 KB Created: 2021-09-20 00:14:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0f933352c9475464f9b2140237b95e72 SHA-1: 882ff11824d01a36a2cba28deb2f523a7ed00270 SHA-256: 19cd54387f9957a183eac1262a71878d70a8b895029079fc64d88f3083a3de56
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including ClamAV and an ML classifier, as malicious. It contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting it functions as a link farm to distribute malicious content or phish users. The presence of external URI links and the overall structure indicate an attempt to redirect users to potentially harmful destinations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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.
  • 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://cructi.ru/uplcv?utm_term=how+to+transfer+subway+surfers+data+from+android+to+ios
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/p1eibohm7882of816ndeonikj5/64901783311.pdf
    • http://fixafilm.se/userfiles/file/muwapijiruwomi.pdf
    • http://ytovietnam.net/ckfinder/userfiles/files/81073451904.pdf
    • http://a-b-i-s.net/layout/bilder/file/fitigezogezavajepuxu.pdf
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f43fa63d89---pivujejikodu.pdf
    • https://www.smartfutureexpo.com/ckfinder/userfiles/files/jatumaruxilinuwefupiguv.pdf
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/8qs6t4at1n5i9fs7dukb1v5v4s/mavibudoposafopoderuzugu.pdf
    • http://kondicionery-shodnya.ru/upload_picture/file/xupavebazop.pdf
    • http://tfe-design.dk/userfiles/file/9131941350.pdf
    • http://mtsp.by/userfiles/files/dofex.pdf
    • http://tainghe.vn/userfiles/file/59836491433.pdf
    • http://kaitianjinghua.cn/admin/userfiles/file/202109161548160077.pdf
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1613556a99a22c---16943954366.pdf
    • https://lensmam.com/userfiles/file/81451517700.pdf
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/6b5fbf60ec143b573e05621647f0e9c4/94410215442.pdf
    • https://thehouseproduction.net/file/60371893754.pdf
    • https://kompaspt2.com/contents/files/gokogozurusakupata.pdf
    • https://simbhaolipower.com/images/file/wazewidomuv.pdf
    • https://invision.buzyhub.com/files/6656749687.pdf
    • http://yuc-fac.com/uploadfiles/20210912044517.pdf
    • http://infiniti.e-library.tw/uploads/files/tipon.pdf
    • http://historia-bfured.hu/userfiles/file/82877087234.pdf
    • https://bienenaktuell.com/sites/bienenaktuell.com/files/file/71406227267.pdf
    • http://dr-temt.ru/images/file/torabinitomubem.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cc44.bin
8fb1a3136ec9ba859309facfd363ac5a4c482ba7d90212f687c5f6f86ebc3d58
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC44 17972 bytes
font_01_sfnt_off0000fa91.bin
8146e87dc9000bca0466488d51bcb21b01c1a5fcd0ccc761b0e79b814c1959f5
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA91 10900 bytes
font_02_sfnt_off000113d5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x113D5 16792 bytes