Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c21840fa210bba5…

MALICIOUS

PDF

81.5 KB Created: 2021-09-16 22:34:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ff6cffd29b81e68d2648b3f93da73185 SHA-1: 1396a33f2dbe9a241ecc470674848764a1658ef3 SHA-256: 5c21840fa210bba5c8bb3a6cc87dc7f74d0e4ae781febb80735442b17321c8ce
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous external URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The presence of external URIs and link farm heuristics indicates a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://garglob.ru/uplcv?utm_term=pet+rescue+saga+hack PDF link annotation
    • https://itchanoi.vn/uploads/news_file/zuruxukevojugamer.pdfIn PDF document text
    • https://ibericadearmerias.com/file/89765936505.pdfIn PDF document text
    • https://onlineadda.organicemall.com/ckfinder/userfiles/files/35957328887.pdfIn PDF document text
    • http://sevennews.com.br/ckfinder/userfiles/files/texexokopuj.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161381d2770802---fabatuluramikarevijovobit.pdfIn PDF document text
    • https://infotechb2blite.com/bot/ckfinder/uf/files/59199286928.pdfIn PDF document text
    • http://pattarasawat.com/ckfinder/userfiles/files/kezaxazomazeruxewewep.pdfIn PDF document text
    • http://sobinco.cz/ckfinder/userfiles/files/vesisepu.pdfIn PDF document text
    • http://tacchigroup.com/public/thread/risorse/file/11889954313.pdfIn PDF document text
    • https://silverstonedevelopments.com/ckfinder/userfiles/files/wujevomutulirilaxuzesix.pdfIn PDF document text
    • https://matras-matrasych96.ru/admin/ckfinder/userfiles/files/75434415206.pdfIn PDF document text
    • https://n-vv.dk/userfiles/file/78261724506.pdfIn PDF document text
    • https://dhesient.com/media/xojakodosotisoguwe.pdfIn PDF document text
    • https://learnrkbin.jugalbandiresearch.com/ckfinder/userfiles/files/64662985008.pdfIn PDF document text
    • https://apluskleaning.com/admin/images/file/gamivatomuzokovetodowede.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/161345c705e3a4---6239814067.pdfIn PDF document text
    • http://namadagaskare.ru/ckfinder/userfiles/files/banasesanuwolosuvotifelin.pdfIn PDF document text
    • http://sangtaoad.com/uploads/userfiles/file/viwunupegagapipalogu.pdfIn PDF document text
    • http://sosonomo.com/ckfinder/userfiles/files/64895715626.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16132562e3cc67---zedonowojifanumegidufe.pdfIn PDF document text
    • http://graciaindoutama.com/kingkong/userfiles/files/wuzesuvesogokisumusul.pdfIn PDF document text
    • http://flirtproducties.nl/ckfinder/userfiles/files/zefef.pdfIn PDF document text
    • http://orkoien.com/userfiles/files/kalavujisomesa.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_off0000d822.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD822 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f034.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF034 18728 bytes
SHA-256: 00272ede22fc1aeaabeb5bd44f7f53aceb517696045d3865d6a35f31335091e4
font_02_sfnt_off00012122.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12122 10340 bytes
SHA-256: abf689b6e1fb2ce27f195035be4ca81854e3f5c16e83bba47d3b7da59354940f