Malicious PDF — malware analysis report

Static analysis result for SHA-256 b844cfc1b72cfb54…

MALICIOUS

PDF

90.8 KB Created: 2021-07-03 10:51:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 491fd616c95301d34e4ceac9acedf017 SHA-1: 55ee1fdef09ac5bbddffa9d1c5d97e7c426c7324 SHA-256: b844cfc1b72cfb5461619bc39ea19b636e85ce9e7af6c13ed962ff25386f58c8
156 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various websites, many of which are hosted on compromised WordPress installations or disposable domains. This behavior is characteristic of a link farm designed to distribute phishing content or malware. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://cplastik.cz/data/cms/file/xitenutikagutalibiruweju.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/4d1vg8t4uo0rjo044g82s9tv07/75855939702.pdf
    • http://bpabv.nl/uploadfiles/file/8782273167.pdf
    • http://midiabyz.com/wp-content/plugins/super-forms/uploads/php/files/63803c7f78155fb5bb6e2a8df91700a0/17506403769.pdf
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/11efe9f47afe09ae48637331afbdf382/pizoremasewedosalurut.pdf
    • http://clubchic.lv/c/i/files/81133573361.pdf
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/0lvfh7ncohvttctp8psolgqd97/87753752224.pdf
    • https://www.karavanlakesfet.com/wp-content/plugins/super-forms/uploads/php/files/d32d260d5d39157f1fba56b24c12dfb6/zikagotawenizebi.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ac133c8770c---menewowanilit.pdf
    • http://hainescentreasia.com/images/file/64384869729.pdf
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e78ebdffce---lurabugawavadog.pdf
    • http://fitsiluet.cz/data/file/zuforemu.pdf
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087e1cdbb978---83000138397.pdf
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/837b7e4e30894776bc3350637c31b7eb/dumiwen.pdf
    • https://tskrea.com/userfiles/file/piboleduwi.pdf
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/5ja93so5rl4cre6dubicnu3go3/37282961906.pdf
    • http://the100voicesofgospel.de/fichiers/newsletter/file/58787562191.pdf
    • https://serka.com/serka/upload/files/9849332257.pdf
    • https://b2cexpressdemo.com/userfiles/file/zojefevepigiwotif.pdf
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/4gmnutimh9jgfj1n88hl7pjoq3/jagenudol.pdf
    • https://kund-in.com/userfiles/file/kimabelidejozujev.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=the+professor+and+the+madman+book+pdf
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a433c82ba65---53211543658.pdf
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b47a81352e3---busumirudopiragax.pdf
    • 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_off0000fef1.bin
362e8ce55019217839510ee1248464f58e83db098e6aa682e06196f22781ecc8
pdf-font-stream PDF embedded font (sfnt) at offset 0xFEF1 17108 bytes
font_01_sfnt_off00012b7e.bin
f08a020bdf91af249ad40bbf5e8287c4071f24064b95a6e142de4f1c1b61b314
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B7E 10820 bytes
font_02_sfnt_off0001440f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1440F 16792 bytes