Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc8619b7630ec13f…

MALICIOUS

PDF

84.1 KB Created: 2021-09-02 05:11:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 7e41bbd6517fdfceed73d8891a191aaf SHA-1: c35f507788f48760d1bf9a253be6052b9fb3ef14 SHA-256: dc8619b7630ec13f7ba57e37036b527ccb13adb252923fce5370c2adec9d2a71
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, many hosted on compromised CMS uploads. The document body is heavily obfuscated and unreadable, suggesting it's designed to conceal its malicious intent rather than convey information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608149f84fed2---1741288515.pdf In PDF document text
    • http://tz5168.com/uploadfile/image/2021/07/23/file/20210723_144542_135.pdfIn PDF document text
    • https://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607b5e0129983---65594351369.pdfIn PDF document text
    • http://rogo-rotterdam.nl/files/zunafakatuxoxuxegifi.pdfIn PDF document text
    • https://tranduongauto.com/app/webroot/files/images/pages/files/36499607232.pdfIn PDF document text
    • https://giriconsultancy.com/content_files/files/dijukenurisurijurevuru.pdfIn PDF document text
    • http://omonetach.pl/foto/ilustracje/file/26279842702.pdfIn PDF document text
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/7dfd913d2d99a97fe1ed0ecd4aed79ab/gusofozuzajejup.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078062a81747---pexurufiwavox.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/bed62bb314f7d70a5218cc23f5da29f9/sosowudogowuro.pdfIn PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/89d37ef923335dc402050842d1168b24/20199064115.pdfIn PDF document text
    • http://funperm.ru/content/file/jevedivok.pdfIn PDF document text
    • http://salukool.ee/upload/userfiles/file/boroxibu.pdfIn PDF document text
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/3b5f3bd437bbb29d57f01ffd4d28682a/pinumogakutakupawirazesut.pdfIn PDF document text
    • https://corghialberti.it/file/96999534427.pdfIn PDF document text
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/f427bcd6aff17178f0215b2b3dfd7b44/vanavixijurefek.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607c5280b7e9a---16465356092.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16123950daf5f7---29102861031.pdfIn PDF document text
    • http://malopolskiszlakwinny.pl/upload/File/92138526764.pdfIn PDF document text
    • http://lamorenj.com/userfiles/files/fozobenekironolov.pdfIn PDF document text
    • http://giteduguedesboires.fr/userfiles/file/gumawogolivurifi.pdfIn PDF document text
    • http://pjzhengwang.com/upload/file/20210723_054833_146.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/vimufaloliwepiloz.pdfIn PDF document text
    • http://www.zywawiara.pl/pliki/11350890601.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=how+to+calculate+the+perimeter+of+an+isosceles+trianglePDF 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_off0000dc92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC92 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f4a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4A9 11104 bytes
SHA-256: 793ab208a2ada910f02ab784f04e04884afced33d643c92e07b5ee23fd4c9a7b
font_02_sfnt_off00010e66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E66 19788 bytes
SHA-256: 175e4ecdc79bca0abbf879663f488f68607fa1ff725cdc59701e7778cbee1525