Malicious PDF — malware analysis report

Static analysis result for SHA-256 51f7b56fcf2ae8df…

MALICIOUS

PDF

84.8 KB Created: 2021-08-19 09:25:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: bc41df3da10c3f546c5c7e523e07b13a SHA-1: 74a5ad756529431304c9daea1e0c853ea2afbda5 SHA-256: 51f7b56fcf2ae8df4589cb93a175e68564ada83d288bce7696b1a62dfb3c9344
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. It contains numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute malicious content or engage in SEO poisoning. No scripts were extracted, but the PDF structure and URL patterns are indicative of a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://www.awakohchang.com/image/upload/File/ajidolor.pdf In PDF document text
    • http://gadkowski.pl/repository/filemanager/file/99354895416.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/cf5986f31b48b4e61c14839a00da358b/60714536505.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160bce02c07974---borijegewe.pdfIn PDF document text
    • http://mateuszkucharski.pl/admin/file/6036508685.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ae5f5de7b00---pisurivepominifegifiwixe.pdfIn PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/r7c5dc3b4g2ol51lrmf8q5a237/69824371122.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607616ef336ab---tiruwogizetebuv.pdfIn PDF document text
    • https://zzhqhi.com/d/files/83966813870.pdfIn PDF document text
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080999e931ec---85874431342.pdfIn PDF document text
    • http://semihkerpiccilervesupersound.com/upload/file/56914923114.pdfIn PDF document text
    • http://sacmacbook.net/userfiles/file/midudakegovugarujawon.pdfIn PDF document text
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/i5bmlft7ge28j7b4h9u8stmsv6/wifovodabalelivixamabar.pdfIn PDF document text
    • https://www.aukuras.org/ckfinder/userfiles/files/badumo.pdfIn PDF document text
    • http://bielwod.com/userfiles/file/gajinopu.pdfIn PDF document text
    • http://simonhoirup.dk/userfiles/file/13597268025.pdfIn PDF document text
    • http://www.deco-interieure.com/userfiles/file/zubededogikuvomekixokus.pdfIn PDF document text
    • https://lion-trading.co.uk/wp-content/plugins/super-forms/uploads/php/files/ilhi80fm2j9r078q2v1dtqv2gv/lexavitunazizilekosupose.pdfIn PDF document text
    • http://platcometals.com/images/file/xawanuk.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/160705e77a646e---16009346028.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/16092dd6fcff54---36369311451.pdfIn PDF document text
    • https://pediatricpotentialsnj.com/PP/PPpng/files/95006974692.pdfIn PDF document text
    • http://xedaptap.net/userfiles/file/82804029955.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=solucionario+matem%C3%A1ticas+aplicadas+a+las+ciencias+sociales+1+bachillerato+sm+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_off0000df92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF92 18456 bytes
SHA-256: 6ccc1cea668dc80551d98105fc87132115b450a88f07c9eda0967a2c842f6432
font_01_sfnt_off00010e79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E79 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012690.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12690 11432 bytes
SHA-256: 60d4b03755276f7f9fa7342c91f8ce06c6f78d5d5d090169b7be4b929d596a00