Malicious PDF — malware analysis report

Static analysis result for SHA-256 28c25fa71448cde0…

MALICIOUS

PDF

71.5 KB Created: 2021-09-04 12:52:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 44670a1b15b0deb639f000442fc473bb SHA-1: fb4b5fb014d6459ec18d4ec008d3561e1baac4c1 SHA-256: 28c25fa71448cde0098188e36baa04cd189a86d759527dd5589bf3e19746d0c7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking readable content but reinforcing the nature of the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://elfuklid.cz/foto/Image/file/volibiseregobexov.pdf In PDF document text
    • https://sgdivorcelawyers.com/wp-content/plugins/super-forms/uploads/php/files/ca7db2dd27ff9974e08b789270630265/wifegimetufitegijavusemi.pdfIn PDF document text
    • https://ols.lighting/wp-content/plugins/super-forms/uploads/php/files/d610a0c1f6c07d3db4319ca08ad3c35b/zipotunexadeguzodev.pdfIn PDF document text
    • https://tortugafilms.ca/adminfiles/file/8330733761.pdfIn PDF document text
    • http://toyotarent.kr/FileData/ckfinder/files/20210527_945DDFB6B9F2CFB7.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/16077bbd51db58---32169990998.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c4c847930b---lunofexenakupivuvijapig.pdfIn PDF document text
    • https://charterfori.ir/basefile/charterforiir/files/13490722861.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c5090d826b5---poturarina.pdfIn PDF document text
    • http://lookkorea.net/userfiles/file/lidafexexow.pdfIn PDF document text
    • http://anvlaw.com/userfiles/file/pimivozubewadatu.pdfIn PDF document text
    • https://veterinarycarefoundation.org/userfiles/file/bevusopapizizoz.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/96f5lhg4t3rkirh9odd8cubh4k/kosabavekukexojadit.pdfIn PDF document text
    • https://ijtm.in/userfiles/file/loviz.pdfIn PDF document text
    • http://turagent007.ru/userfiles/file/vepozovubabewuziremaz.pdfIn PDF document text
    • http://veterina-hrib.cz/user-uploads/files/99530237782.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/653565c8f70b92ac47a58184914cd142/jakokofo.pdfIn PDF document text
    • https://brandonsmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/fcm9c3k9ftf42krvf2g1ra4h86/47729710946.pdfIn PDF document text
    • http://mateuszkucharski.pl/admin/file/wemigorafasofubajofepon.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/46305075378.pdfIn PDF document text
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/5mnijqjkctbkodgmts1b50r5us/mizikebulabeke.pdfIn PDF document text
    • http://arisutour.com/ckupload/files/fevagugozitexire.pdfIn PDF document text
    • http://aivieksteslaivas.lv/userfiles/file/jidenuveduwar.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=binomial+probability+practice+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_off0000b74f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB74F 10920 bytes
SHA-256: 00dad2914ff5c7976e44dc1173acf85235069823b52ee28b3d3ea5e2ded79168
font_01_sfnt_off0000d05e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD05E 15588 bytes
SHA-256: 096ff8b6fc80ae8c0443efb208e0fe21a840de333444be0fccdc7d43b271e2ca
font_02_sfnt_off0000f820.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF820 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

Open this report in the interactive analyzer, or submit your own file for analysis.