Malicious PDF — malware analysis report

Static analysis result for SHA-256 e99ca4aac1c56c57…

MALICIOUS

PDF

84.7 KB Created: 2021-08-28 12:54:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 867da9cd31f043e1c40bb96b137623e0 SHA-1: cb1024230e2f85c41fa3f058fa872fb3f600a5e8 SHA-256: e99ca4aac1c56c573950928f035ebc27220aa5b0c8fc11a5d52b0fe53fbcd9d6
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to various domains, many of which are hosted on potentially compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The file's structure as a link farm suggests an attempt to obscure the ultimate destination or to leverage SEO poisoning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9938

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://asja.ua/userfiles/file/84065758708.pdf In PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/b24b268797f3b1d5038c3823b8240497/fefixi.pdfIn PDF document text
    • http://mmckno2010.zkosuchdol.info/files/48935328021.pdfIn PDF document text
    • http://eco-versute.com/app/webroot/ckfinder/userfiles/files/7577307790.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a7d8ecbbd43---wekumudulefuz.pdfIn PDF document text
    • https://www.dartmusicfestival.co.uk/wp-content/plugins/super-forms/uploads/php/files/e0f80405e20ce08c01613cf1372ad846/99171523516.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cf3e187b1f3---70337236340.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609cbf0c97aee---7202834462.pdfIn PDF document text
    • https://lightspec.ca/wp-content/plugins/super-forms/uploads/php/files/fb8fe967ae0965a1cc4ab1ce34ad15a1/67812841910.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/e7a4d5541cd21b464573cf010cf18c59/37062525663.pdfIn PDF document text
    • http://romovi.net/sgi_userfiles/userfiles/files/82829679571.pdfIn PDF document text
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8c11c6902---vukebexemil.pdfIn PDF document text
    • http://thermocomfort.ca/userfiles/file/33646850551.pdfIn PDF document text
    • http://cobe-ing.it/userfiles/files/tunenubevizovoba.pdfIn PDF document text
    • http://telegid.tv/userfiles/files/64897768131.pdfIn PDF document text
    • https://marblobath.com/app/webroot/img/files/52526092325.pdfIn PDF document text
    • http://steinemann-ag.ru/nijerekepuzotopim.pdfIn PDF document text
    • http://dj-venci.com/uploads/pages/files/kememukusenuborawegili.pdfIn PDF document text
    • http://caratow.nl/userfiles/file/fekalexutojududira.pdfIn PDF document text
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/c12ee3cdee7f0c178ed7edda0bc58929/20426234589.pdfIn PDF document text
    • https://www.apollopowersystems.com/wp-content/plugins/super-forms/uploads/php/files/c2e62c6b81913e52eeb8d0c7ddfdc9a5/lifokuwonisexonifuk.pdfIn PDF document text
    • http://ccforum.kr/uploads/file/1623774820.pdfIn PDF document text
    • https://crossfitbeeshark.ro/app/webroot/files/userfiles/files/57559866961.pdfIn PDF document text
    • http://marjoleintje.nl/include/userfiles/nulekiwabalogibagaze.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/d6b6efdda78867800eecad10983b3bb5/zipasaxipamujevikafuw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=tokyo+ghoul+first+openingPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cd61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD61 18824 bytes
SHA-256: 7fc1e4f302d30c12a68e77b9ade984a38794b432a734eedd198e379b1d4d6f03
font_01_sfnt_off0000fd16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD16 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001152d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1152D 10744 bytes
SHA-256: 4935b55094aae7b7d761641abc7f3f55bab45de99431ed33014fa8c70474b6c1
font_03_sfnt_off00012ddc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DDC 16164 bytes
SHA-256: a0f26d9ec2bc0bbc84dfb8c1a224a49f7f70479ac92e21d726acd811d43f3bd1