Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ffd4d2b37a47bbc…

MALICIOUS

PDF

86.4 KB Created: 2021-06-26 22:17:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4423fb8e0e16433a93ae8399bd2d9a63 SHA-1: 1a2ac361f4169381254912bb1d586648db87f853 SHA-256: 8ffd4d2b37a47bbce28008b0b490a0ac880e7db1c419c901e408efd7d79ef85e
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites hosting other PDF files. This behavior is indicative of a link farm designed to redirect users to malicious destinations, likely for phishing or further malware delivery. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608050ff63390---60950839188.pdf
    • http://recrute.fr/files/files/gitepinamujaz.pdf
    • http://apartmaji-zunicmile.com/uporabnik/file/firozarenorubojamamume.pdf
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b74bc1957b2---danizef.pdf
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16073a3c731b71---79197132934.pdf
    • http://hopkinshigh1988.com/clients/75739/File/59183711982.pdf
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c4f2af3532e---11685672477.pdf
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/d241c8df4e9f6d9ae37b13812c042183/rinabusararam.pdf
    • https://banghenails.com/upload/file/40482034135.pdf
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/3b5k67rn6qs5043l7bdqm82ar8/43526348940.pdf
    • https://xn--arbeitskndigungsrecht-best-5zc.de/userfiles/file/gimobewabe.pdf
    • http://gesundezellen.de/neu/userfiles/file/18564112316.pdf
    • https://sasalidayanisma.org/uploads/file/nebezuxatajet.pdf
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a90f3b1fe25---vimeto.pdf
    • http://infinity-pro.ru/userfiles/file/zoderolulalujago.pdf
    • http://www.ecvbrass.ch/user/web/file/87170705055.pdf
    • https://investmentskillsgroup.com/images/userfiles/file/gesifuxikekewubexagajevob.pdf
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd794c2ef77---xenufukonimupukurixiluzu.pdf
    • http://studiopol.com/userfiles/files/15827479749.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609f9eb6b0beb---vidubav.pdf
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c48177d10c5---kiwukolorubupakopab.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=sublet+lease+meaning
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef3c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF3C 16792 bytes
font_01_sfnt_off0001074e.bin
d76268a2431a89ee57909612783aab4ad49abd97b395b8e42e2c680f6f6a37e6
pdf-font-stream PDF embedded font (sfnt) at offset 0x1074E 17328 bytes
font_02_sfnt_off00013492.bin
9a41edc516d645244b70628576d2d9d343b2973e790bac90d0950a602f24c628
pdf-font-stream PDF embedded font (sfnt) at offset 0x13492 10548 bytes