Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6dcb4baa4129241…

MALICIOUS

PDF

78.2 KB Created: 2021-09-05 14:59:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f8b6a1d67b3829dfdd9b819e137dc31b SHA-1: 5c3ccfe463744056664ed2dffcd192a7e1acbc37 SHA-256: b6dcb4baa4129241dc9b071bbfec04ce65c48fefae08ef608f60f2bf35e4850d
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting it's used to distribute further malicious content. The presence of numerous unknown URLs reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://ensasoft.com.tr/wp-content/plugins/super-forms/uploads/php/files/j4kjtkrhqeh544a5m9fcrro2oq/wavupurituxejusejafoxaxi.pdf In PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa8e9c46594---20904952388.pdfIn PDF document text
    • http://mim2010.ru/userfiles/file/tunisovitotitegofoxom.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0d3b49dfd---muxuzefuraporav.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/61f541c11905d3c5beddf9cc2fb84f23/liralixakevavadijenugabi.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095b73049844---20493373617.pdfIn PDF document text
    • https://malashealthcare.com/userfiles/files/burajobow.pdfIn PDF document text
    • http://emachn.com//data/attachment/file/tirigudibusol.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/xivesobagugizo.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608684ed4843f---besawoluza.pdfIn PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/5d68b54778bfc88778ba0420ba4907f4/52558871584.pdfIn PDF document text
    • https://nwdglobal.com/ckfinder/userfiles/files/nutefikuvadaman.pdfIn PDF document text
    • http://evergladesharvesting.com/ckfinder/userfiles/files/detufibesusawinemi.pdfIn PDF document text
    • https://zippy-inc.com/app/webroot/userfiles/files/66050251580.pdfIn PDF document text
    • https://soba05.org/wp-content/plugins/super-forms/uploads/php/files/304601206b63902edc881a6eb06017f2/dugarozisixapap.pdfIn PDF document text
    • http://vdadanang.vn/app/webroot/assets/files/vinutezegogi.pdfIn PDF document text
    • http://soles2walk.cz/data/file/90218162349.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca43029980---totumabux.pdfIn PDF document text
    • http://pincesorvarshop.hu/editor_up/kakutidusumapewib.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/31524137915.pdfIn PDF document text
    • https://rivaflo-south.in/userfiles/files/9914891088.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3a0d244a9f---pukazanonike.pdfIn PDF document text
    • https://solelane.com/ckfinder/userfiles/files/35225840265.pdfIn PDF document text
    • http://royalleasingny.com/admin/images/file/jumiparinep.pdfIn PDF document text
    • http://www.teeintact.com/admin/fckeditor/editor/filemanager/connectors/php/img/file/3105151308.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=walt+whitman+leaves+of+grass+poem+pdfPDF 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_off0000ccba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCBA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e4cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4CC 17284 bytes
SHA-256: 4418cc8aeb8f944dcc5792a64732e2c5dea841a8f54b4b8dac30bcd3f9ec157a
font_02_sfnt_off0001110c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1110C 11092 bytes
SHA-256: 2687025a2f3e3ec336c18c8c08e6d3845f989d5774a31910951300ed0b189c79