Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd57b7d738e5c625…

MALICIOUS

PDF

75.0 KB Created: 2021-09-07 07:47:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 454179df4ae9042370456fafc29d671c SHA-1: 1baa0c2c62866f0f2006ea09e6f4698a08c125e4 SHA-256: cd57b7d738e5c625ab98310a8983afa1cae1f6147682497dd721e718c022cf6b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to potentially compromised WordPress uploads and disposable hosting, suggesting it's used to distribute further malicious content. The embedded URLs, while some are marked benign, are part of a larger pattern of redirecting users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9885

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 http://hud101.vn/webroot/img/posts/files/96227664481.pdf
    • http://muzycznescyzoryki.pl/userfiles/file/mexag.pdf
    • https://flyingfish-stay.com/userfiles/file/vijikirelopig.pdf
    • http://liebherr-tr.com/userfiles/file/tadegaxukokid.pdf
    • http://hanhthien.net/uploads/file/94193563279.pdf
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609e88246308a---dexavojopuxoxirazela.pdf
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/16090f49dc3268---42799572149.pdf
    • http://somersetcountybar.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/30021014054.pdf
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16083f7dbbfc21---vokabepejudogudomamag.pdf
    • http://studio5r.com/userfiles/files/40285888259.pdf
    • http://big-blue-bus.com/pics/fotos/1/file/28856848675.pdf
    • http://cuacuonanbinh.com/userfiles/file/miparuko.pdf
    • https://chinese-wall.tw/upload/files/kobumunarinotoduvazob.pdf
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/pg99dhoh3h1csnq5a833mrnta3/13880440852.pdf
    • http://www.elstar.ru/uploads/files/9845826073.pdf
    • http://urbancollab.com/userfiles/Proj_Name//files/72282659243.pdf
    • https://biblioteka-koneck.pl/ckfinder/userfiles/files/30372626632.pdf
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607327b47f908---puvanenemoliwegu.pdf
    • http://langeline.com/ckeditor/upload/files/33846512812.pdf
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/h0l0m0gf19qs1aeslsjgip3ste/xogugulolevisiveba.pdf
    • https://audit-advisers.com/userfiles/file/voporodizab.pdf
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091f226eb27c---fonigedodorefuv.pdf
    • https://eventpro-kontraktorpameran.com/uploaded/files/kawizazewuwevutiduguvuvo.pdf
    • http://verynailscm.com/user_img/file/38703256055.pdf
    • http://www.eau-msu.ru/ckfinder/userfiles/files/80679180997.pdf
    • http://beloezoloto.ru/userfiles/file/91740790060.pdf
    • http://soc-in.com/data/media/files/vadadodumijozugivafexana.pdf
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/h44kloif542qevk090ltqk0d68/39282750531.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=evan+moor+reading+comprehension+grade+4+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_off0000c3c6.bin
4187cd572f65f3a8e69894968bfd31ac82eccad34e6fd4d665a0673a70bd3550
pdf-font-stream PDF embedded font (sfnt) at offset 0xC3C6 16096 bytes
font_01_sfnt_off0000ecaa.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xECAA 16792 bytes
font_02_sfnt_off000104c1.bin
8e50add0aea13726fd45db771e944f2f8f6fd2bff4b72cb0d7f629d4a79cb01f
pdf-font-stream PDF embedded font (sfnt) at offset 0x104C1 11048 bytes