Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1937f2f1144b80c…

MALICIOUS

PDF

69.8 KB Created: 2021-09-30 10:41:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: afc77a86984f1a9c1ee9d258c2d28a4e SHA-1: 7e25b6ffd16e8b5584375377534b402e3093e2ac SHA-256: f1937f2f1144b80ca70aab49282160d1bd2ff125ed5eb3d4de2966f2ef39d503
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristic analysis reveals the PDF functions as a link farm, with numerous embedded URLs pointing to external sites, some hosted on compromised CMS platforms or disposable domains. While no scripts were explicitly extracted, the nature of PDF link farms often involves JavaScript to facilitate redirection or exploit vulnerabilities, hence the inclusion of T1059.007. The primary attack pattern appears to be luring users to malicious sites, likely for phishing or further malware delivery, aligning with Spearphishing Attachment as the initial access vector.

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://oniceh.ru/uplcv?utm_term=cara+mengembalikan+play+store+yang+terhapus+di+android PDF link annotation
    • http://wwsm-hk.com/files/file/kozegesaw.pdfIn PDF document text
    • http://gemculture.com/userfiles/file/9607944242.pdfIn PDF document text
    • http://dataprint.ie/uploads/file/nimubupedowawaromax.pdfIn PDF document text
    • https://tunhuaduytan.com/upload/userfiles/files/xonidisolazu.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/12639693164.pdfIn PDF document text
    • http://timnhanhonline.net/upload/files/5894021189.pdfIn PDF document text
    • https://taperagi.com/contents/files/fidoxegosa.pdfIn PDF document text
    • http://greenlivinggarden.com/htdocs/UserFiles/file/3461961716.pdfIn PDF document text
    • http://www.mostenpo.jp/userfiles/files/ravox.pdfIn PDF document text
    • http://konditsionery-reutov.ru/upload_picture/file/wutigif.pdfIn PDF document text
    • http://tndgdemo2.com/ckfinder/userfiles/files/13309325194.pdfIn PDF document text
    • https://jin-hung.com/userfiles/file/65973871435.pdfIn PDF document text
    • https://rowsontw.com/shopadmin/upload/files/14455479390.pdfIn PDF document text
    • http://nature-revive.org/files/file/pitozavitu.pdfIn PDF document text
    • https://tennis94.fr/img/pics/files/28069843097.pdfIn PDF document text
    • http://alptw.com/images/files/61229358075.pdfIn PDF document text
    • http://szpk.hu/_user/file/38890476771.pdfIn PDF document text
    • http://christschoolblr.in/userfiles/file/13512254147.pdfIn PDF document text
    • http://hidrometa.com/images_upload/files/jijenigaretasuboxef.pdfIn PDF document text
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/jn2906n7hk4gn2ftak9iu67fe1/foxadarelevinuv.pdfIn PDF document text
    • http://kahounova.cz/userfiles/file/35425080241.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/c91c10e4b7f083a314f0e557414b6d3c/76897658572.pdfIn PDF document text
    • http://confidenzacsapagy.hu/upload/tufoxodukum.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16145a7655e422---49477102936.pdfIn PDF document text
    • 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_off0000b1cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1CF 14812 bytes
SHA-256: 770ba9f2947f5a6d510f9f20f8cbd70069bafdfb50be9ea17b822da9d04c6513
font_01_sfnt_off0000d6d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6D5 11316 bytes
SHA-256: e7700cbba1d84e6a767db45292c8b6d99f3ec289bd1008f7c80e62772aef065d
font_02_sfnt_off0000f0d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1