Malicious PDF — malware analysis report

Static analysis result for SHA-256 421cfd805d3c8586…

MALICIOUS

PDF

99.8 KB Created: 2021-08-15 04:42:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5d5e44f7dd6d9ed55a006dfa5ebc4f09 SHA-1: ad4a582993b174dead723c50a569704b6e23d586 SHA-256: 421cfd805d3c85861b7758d9b6af9c08f9c1d7b9b7792eeedb5cc70a37f3a052
172 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript, which is often used to initiate malicious actions. The file also exhibits characteristics of a link farm, with numerous URLs pointing to potentially compromised or disposable hosting, suggesting an attempt to obscure the final malicious destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

Heuristics 8

  • 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.
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://irrisyst.eu/files/file/zedezoxebi.pdf
    • http://happyhanool.com/ckupload/files/95566965793.pdf
    • https://www.charroninc.com/wp-content/plugins/super-forms/uploads/php/files/698cce87c9c84c21ca28dededfba85a1/41705209643.pdf
    • https://angkoronetour.com/userfiles/file/fuwiwedudeteji.pdf
    • https://honkakuji.jp/honkakuji/images/ckfinder/files/2001776483.pdf
    • http://k-ookuma.com/js/upload/files/jubagavaniputubif.pdf
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/d395bcb9a639eabe8a0a9aeddce65ca3/bukadijiliwizetev.pdf
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0136b65731---30691676411.pdf
    • http://atthaya.com/file_media/file_image/file/mamemagadijunu.pdf
    • http://steelfurniturecn.com/d/files/5336904000.pdf
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c6936e3a9f9---vubitatologaz.pdf
    • https://msr-hudsonproperties.com/wp-content/plugins/super-forms/uploads/php/files/77e0e13fe9a35f6f998c46604ad1d14c/zafinu.pdf
    • http://splogservice.ru/content/file/23833051227.pdf
    • http://platcometals.com/images/file/61712242896.pdf
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/161182f28d7a3f---gomajorekirijugolivod.pdf
    • http://wurbs-hanau.de/userfiles/file/jakako.pdf
    • https://ceilford.org/wp-content/plugins/super-forms/uploads/php/files/f2b3bd071030f1262a1952344427e91a/91830587692.pdf
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc390a2e93c---10692872468.pdf
    • https://ip-pharma.net/data/files/votabumu.pdf
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1607b08ca8aadc---zivegozagukunejulegafe.pdf
    • https://e-lightingcontrols.com/wp-content/plugins/super-forms/uploads/php/files/27e21335bda2fa2ed7856f1806f8a033/melutuxegejegejasefuwoxug.pdf
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071a47a883a2---nojakamidugekoworo.pdf
    • http://www.awakohchang.com/image/upload/File/0732004013.pdf
    • http://fedoro.ru/upload/file/degigovojokulagenafuxe.pdf
    • http://hyunbulsa.org/~ewedd2/userfiles/file/42336293975.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=chug+jug+sound+effect
    • 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_off00011b93.bin
ee95938498a2832be58dc00678901156806dc162703f6e4b0a0b0e858d8ef216
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B93 20496 bytes
font_01_sfnt_off000151c1.bin
a370e1ebe52b13bc8d48e4ebe84fbed3c98be937288c048949ff8c3ce9283d22
pdf-font-stream PDF embedded font (sfnt) at offset 0x151C1 10616 bytes
font_02_sfnt_off000169d9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x169D9 16792 bytes