Malicious PDF — malware analysis report

Static analysis result for SHA-256 de88dd8c0821b6c9…

MALICIOUS

PDF

89.5 KB Created: 2021-06-26 03:16:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: a41e3afc328eae29e32bc23fca798731 SHA-1: 740564760283a0928637a2791d1be26c6494c481 SHA-256: de88dd8c0821b6c97c2a594e118cadf24518d18f85383e37f7059b7784429b9d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are identified as compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated, but the heuristics point to a link farm designed to redirect users to potentially malicious content hosted on compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d538d4644d---57046783958.pdf In PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/668daba4ca5b5b23a375ed0c2a9c1f86/walabowexux.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcaa0752e8b---40377930292.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1607217c4da807---nixigexukowusadabupuruzu.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607fc0347f9d2---zufozojejonerogodupav.pdfIn PDF document text
    • https://xn--mgbaf4adbs1bd2i.net/upload/ckfinder/files/72778053650.pdfIn PDF document text
    • http://washchienluoc.com/upload/file/jenibexojipijosovewovevub.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c90208393f---bemon.pdfIn PDF document text
    • http://affordableadobe.com/ckfinder/userfiles/files/57107555047.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/ekjpeh2ngjn9sctrrf13ah052j/51552092349.pdfIn PDF document text
    • https://spaslask.pl/wp-content/plugins/super-forms/uploads/php/files/6a7ur17kaqmc4aqo81hfv23q5i/61185319806.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/646151aa18d2aeaa31cb20c4506be03b/bipirazanirosibajotet.pdfIn PDF document text
    • http://gadkowski.pl/repository/filemanager/file/33920615165.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/c46f37eec69f460720931339c5ef9750/luviro.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/965a3ff12bee44a7dda6b1d0fe12b478/48833460992.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b1879ccd51---natololep.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20210509125704.pdfIn PDF document text
    • http://panda-es.tokyo/yamituki-n/uploads/files/lavanesutegelerogilozulom.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/52fd935448199ccea48759ae8cf74a79/fotalodujewoxat.pdfIn PDF document text
    • http://angelcabrera.com/FCKfiles/file/39820504868.pdfIn PDF document text
    • https://www.justgym.co.za/wp-content/plugins/super-forms/uploads/php/files/7627q67glh0rclemkvelsqj45i/92055152748.pdfIn PDF document text
    • https://nolimitscenter.be/peausitive/images/FCKeditor/file/zabupigopujesima.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c133d01759d---pitakenegowu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=how+does+the+poem+describe+himPDF 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_off0000fb5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB5E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011370.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11370 17448 bytes
SHA-256: 0d8249eafaf8298a35b910e1ec4fff333dc0c3d5be6b17dd7c08bebdf4b93c05
font_02_sfnt_off000140cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140CD 10684 bytes
SHA-256: 0dd7e9467523b19803208f039a2cf82ea620fe21a1a6a89fd4583308151dff96