Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7428bb8b2b1fca7…

MALICIOUS

PDF

94.2 KB Created: 2021-09-03 08:22:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e4bfb573125dc68fe9ee51bf052acbcd SHA-1: a31b9ca2c0ac61e39ecda24856c4a58cbe5ed7b3 SHA-256: b7428bb8b2b1fca7de5c49a3e2187fe82f0d639664b1bd46d9574cc20e760e1b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code or redirecting users. The numerous external URIs, many pointing to compromised CMS uploads and disposable hosting, indicate a link farm designed to obscure the ultimate destination, likely a phishing or malware distribution site. ClamAV detection and ML classification strongly support the malicious verdict.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 7

  • 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.
  • 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.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb48fb2fc1---ribajajuzenuwabenad.pdf In PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/820ebe0528cfcb9579b7195da5b9dfce/40321824449.pdfIn PDF document text
    • http://nena-artspace.com/ckfinder/userfiles/files/25669764493.pdfIn PDF document text
    • https://guineaservicesproviders.com/gsp/files/88366853033.pdfIn PDF document text
    • http://ilovegabal.net/fckeditor/_upload/file/10930429072.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16098c069705a5---93277389162.pdfIn PDF document text
    • http://worldnaturalfood.com/image/upload/File/22292012531.pdfIn PDF document text
    • https://mumegram.com/userfiles/file/49455675849.pdfIn PDF document text
    • https://emilline.dk/ckfinder/userfiles/files/fidowotoxutikemulupo.pdfIn PDF document text
    • http://kulturazebrak.cz/userfiles/5254417823.pdfIn PDF document text
    • http://www.jamesbgriffinlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b29a33b1d71---xuwegexirefajageziji.pdfIn PDF document text
    • http://www.festivalmarrakech.info/wp-content/plugins/formcraft/file-upload/server/content/files/1607e7c55e5674---19286372090.pdfIn PDF document text
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/16095303d62cf1---17459665314.pdfIn PDF document text
    • http://e-district.org/userfiles/file/tabiwatobazutufiwakita.pdfIn PDF document text
    • http://krr-nfe.com/suratnfe/UserFiles/File/28961633805.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d22cac8cea6---rerowowizoxisitox.pdfIn PDF document text
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/e39c7916d204f237a6902270b38c0991/79411066928.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/0e7189de9b87c8e858504af3407dc816/78667631741.pdfIn PDF document text
    • https://majubesar.org/contents//files/kilosarofamunususefonovo.pdfIn PDF document text
    • https://bdata.vn/upload/files/jatejaxujupaturapijegu.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/kedetuxevusukofe.pdfIn PDF document text
    • http://kasargod.net/uploads/file/bipon.pdfIn PDF document text
    • http://www.jacenter.org/js/ckfinder/userfiles/files/82818302117.pdfIn PDF document text
    • http://3e-machinery.ru/app/webroot/filesfiles/32143244692.pdfIn PDF document text
    • http://haustechnik-hagenauer.at/wubalipazegagitafi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=agricultural+economics+and+agribusiness+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_off0001092a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1092A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001213c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1213C 18580 bytes
SHA-256: e069d46976d29d6f17ebfcc2c139896680f8783f3562e72acf5291ff8dce9aac
font_02_sfnt_off0001511c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1511C 11184 bytes
SHA-256: 43c0802a9c3184eaccf529e40635e747cd79941d6da0f7d78e3f55db878269b4