Malicious PDF — malware analysis report

Static analysis result for SHA-256 a72e3444254ffe7d…

MALICIOUS

PDF

93.8 KB Created: 2021-06-28 23:56:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 792e09a4fca8c224adf81f9f7623ef52 SHA-1: d611484f52baf7b08d9bd516a2a04420fd5fef85 SHA-256: a72e3444254ffe7d8adbed33d460d0754a7fb0dd0e6a9f88de9ffc0f7f57b717
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, with numerous URLs pointing to compromised CMS upload storage and disposable hosting. While no scripts were explicitly extracted, the nature of link farms in PDFs often involves JavaScript to redirect users, suggesting an attempt to lure victims to phishing sites or download further malware. The file was authored by wkhtmltopdf, a tool often used to generate PDFs from web content, which aligns with its function as a link aggregator.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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://guowangcable.com/d/files/lodewalodovarubezexoj.pdf
    • http://robertoantoniz.com/resources/original/file/xorud.pdf
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b393e3410f1---83678399474.pdf
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1607084975ee15---10753495345.pdf
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/2e584faa2f000e85153a1cefb1cce76b/46432960794.pdf
    • https://emmaushuis.org/pages/69700340493.pdf
    • http://anoh.net/pds/userfiles/files/57054992817.pdf
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608620fde4d1f---15089023150.pdf
    • http://murphysbeads.com/clients/54316/File/60281745921.pdf
    • http://barcelonasixtytwo.com/userfiles/file/5375951664.pdf
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a03550c633d---tubokosize.pdf
    • http://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/t7t1v7cvmtc0f2hnc7lbve4nq4/698381545.pdf
    • http://constantcontinuity.com/membership/data//files/24548080642.pdf
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/dd16187332f8fc18993d1070a0dfb2d1/vojexaweziwore.pdf
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/3e62e184d3a4f5054bb2b1c35e547af1/wenuzoti.pdf
    • http://msamerica.net/clients/873634/File/ragoxixamisilufovexerifa.pdf
    • https://laser-arena.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1608ad25c41ad2---68657203510.pdf
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/qus9o1ntjqcvretrhegjbkf7f5/87572574725.pdf
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf110ae833---90894073098.pdf
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/b1mrlv7egkcm93b1k236tujs0o/78091092799.pdf
    • http://macabrey-luthier.fr/data/Files/29846345899.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=farmers+planting+rice
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001056d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1056D 16792 bytes
font_01_sfnt_off00011d84.bin
4d34cdf0ede6debdc7cc1efbd7e605cda10b1019c80044187b2cbe940c270ccf
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D84 10572 bytes
font_02_sfnt_off00013591.bin
6a75b9764b76a2c6f7d152a8c92a24b73a4a005bccce61d7a5a969a6a70935e7
pdf-font-stream PDF embedded font (sfnt) at offset 0x13591 1696 bytes
font_03_sfnt_off00013daa.bin
9980e1ec627064e3bdfa82986b8a17d0e2ec2cb4972ddc7478ed9630b26ced58
pdf-font-stream PDF embedded font (sfnt) at offset 0x13DAA 17052 bytes