Malicious PDF — malware analysis report

Static analysis result for SHA-256 3169d6c56c6aac9e…

MALICIOUS

PDF

87.2 KB Created: 2021-08-06 15:23:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 81479b966454174dfa05fb31f1c985e5 SHA-1: ae8ea8d6ec6ecb3575fb9324637d4cf50e1de429 SHA-256: 3169d6c56c6aac9e67e22546be88bfc7d85ac995e0137a332230ee59f76ba6de
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing a large number of links, many of which point to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the link farm structure itself is a common tactic for initial access via spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://chcial.ru/uplcv?utm_term=chapter+2+the+history+of+barbering+worksheet+answers
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160978f04a7788---53846901122.pdf
    • http://busankid.com/webfiles/board/file///sixotexaza.pdf
    • http://www.klpreschool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fdf294bcb2---82233909441.pdf
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/5c0202a93363c91bd386439096736d4e/63475729563.pdf
    • http://jump360.co/upload/files/20210607081609.pdf
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/f34bd7eaf58cf234f0276a79486ff252/vaxufezukugesodonupe.pdf
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/825e4656daea5bbf72a387b433bc98c8/49773411973.pdf
    • https://yucekalipmakina.com/tsrm1/img/userfiles/file/desegut.pdf
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c229766986---58280486866.pdf
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/2e14ff2c5fce022860ce485f26c4b989/61766308727.pdf
    • http://akademibt.com/resimler/files/sixoxusobelirifexugefex.pdf
    • http://kondicionery-ivanteevka.ru/upload_picture/file/pabutivumelevabor.pdf
    • http://sintellect.ru/Repository/file/kelekozibatunemejexagig.pdf
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ee61ceb7f11---81943842263.pdf
    • http://riph.pl/userfiles/file/19893475261.pdf
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/16081dcff58c7a---notoviguveruz.pdf
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/0bc55772a065d4eb3399b09743d310b3/2902235329.pdf
    • http://tourbusan.net/FileData/ckfinder/files/20210728_1C52192157C80F62.pdf
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1607343ec24104---karutilamejonu.pdf
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4c9a51bdf7---wosomup.pdf
    • http://jyjjapan.jp/files/ckeditor/files/53923553880.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_off0000efe6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFE6 16792 bytes
font_01_sfnt_off000107fd.bin
a021491536484201d2b3a81254072f8fe190d89a7846748ad139063f4f8c2974
pdf-font-stream PDF embedded font (sfnt) at offset 0x107FD 11176 bytes
font_02_sfnt_off00012215.bin
123ff6cb8771a3787f19089ad6e3425fea9bacc81a7005a4bcd33920e5cd2139
pdf-font-stream PDF embedded font (sfnt) at offset 0x12215 17436 bytes