Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff8c9f36c8f98abb…

MALICIOUS

PDF

84.4 KB Created: 2021-09-16 23:02:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 4ab7b94a5f95550df3a5f26cb2817e0d SHA-1: 71338008624ea0d5fdbe36e93cb9cf905626a6e4 SHA-256: ff8c9f36c8f98abb8f287172274315127e9b613d268c84f3db24d7733f144c06
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as a malicious PDF by ClamAV and an ML classifier. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The presence of embedded URLs and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicate an attempt to lure users to potentially malicious websites for phishing or further payload delivery. No scripts were extracted, but the overall structure points to a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://infrive.ru/uplcv?utm_term=jak+sciagnac+aplikacje+na+androida PDF link annotation
    • http://fonnepal.org/userfiles/file/depowaponagiralenerebi.pdfIn PDF document text
    • http://kenhuffbuilders.com/userfiles/file/bijena.pdfIn PDF document text
    • https://purefeeling8.com/data/file/vimiligowu.pdfIn PDF document text
    • http://dekoblickfang.de/userfiles/file/30557307545.pdfIn PDF document text
    • https://sanidom.pl/img/file/komanewarazusanibotemuxa.pdfIn PDF document text
    • http://sandlnae.com/data/editor/file/46368622552.pdfIn PDF document text
    • http://xn----7sbicwad4afgcgd5aph7d5e.xn--p1ai/ckfinder/userfiles/files/80918342402.pdfIn PDF document text
    • http://taociren.com/upload/file/21090100255355887728az5315sk45.pdfIn PDF document text
    • https://vgi-vn.vn/app/webroot/img/files/vujizawasasisibis.pdfIn PDF document text
    • https://smwebtechnology.com/arishayurveda.com/userfiles/file/53428714398.pdfIn PDF document text
    • http://tlxzkj.com/uploads/file/100119344003.pdfIn PDF document text
    • http://edbiji.com/uploads/files/20210911031245_104241.pdfIn PDF document text
    • https://998.geektic.com/geektic/files/wupuvijevudarogikepepe.pdfIn PDF document text
    • http://oroblupiscine.it/userfiles/files/4756159150.pdfIn PDF document text
    • https://siroyensao.com/upload/files/35277215955.pdfIn PDF document text
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/baf9db05fd24c863f86f327706edb76d/47664390759.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/55ee07c8bd0071799fc6eb9a46837190/71436702172.pdfIn PDF document text
    • http://shijijiaming.net/filespath/files/20210904003015.pdfIn PDF document text
    • http://aburobocon2019.mnb.mn/uploads/files/80881186530.pdfIn PDF document text
    • https://insinkerator.us/images/uploaded/file/33810883171.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131652d9e194---87516528889.pdfIn PDF document text
    • https://ijtm.in/userfiles/file/23398963436.pdfIn PDF document text
    • http://meskerjager.nl/media/files/57754246984.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_off0000e69a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE69A 17616 bytes
SHA-256: 773b8221d61e964f8795b2ea32b9eb8231a3a14549444d8febad8d5b4a1c8f8a
font_01_sfnt_off00011310.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11310 10804 bytes
SHA-256: 134d6e16e7c5d68a124c3902b260550099521dba640316c157d2a0271ec9cdea
font_02_sfnt_off00012bd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BD0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1