Malicious PDF — malware analysis report

Static analysis result for SHA-256 51721f9295427df6…

MALICIOUS

PDF

89.3 KB Created: 2021-06-28 01:13:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 154ad41dddc9a39895dbd4a0dfab8058 SHA-1: dd5de1f0631ee7eb4d533c7eebf4b25b2d825f96 SHA-256: 51721f9295427df688142a198f39078fb60c386cbe5894e7c3ab88e51d856554
164 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URIs and link farm patterns, suggesting an attempt to direct users to malicious websites for downloads. The presence of a 'download button' heuristic further supports the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://cructi.ru/uplcv?utm_term=conflict+desert+storm+pc+game+download
    • http://vzwsportenmuziek.com/content_docs/duzolodeniw.pdf
    • http://faw-asia.com/image/upload/files/kilexuno.pdf
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/51de80cca25b266797d7b9979ae86c08/64525118539.pdf
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160b919bbeb428---53447373265.pdf
    • https://brianhigbielaw.com/UserFiles/file/wisiwelorijipetago.pdf
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c1edf2a635---boxuwetatibuxesebipuxete.pdf
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607ffad4524ce---litopojusugojogumilopipem.pdf
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16089c4c81efc8---31758142410.pdf
    • http://kochamsushi.pl/UserFiles/file/99653319176.pdf
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098babf83666---repikibumuwetupazavekadu.pdf
    • http://tjsijiqing.com/ckfinder/userfiles/files/2021/0604/d8b500a01e3e270339d48ed454b970e0.pdf
    • https://gadd-asso.org/userfiles/file/waratezotubox.pdf
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/nma0fnhpomuethb2q48rjljkak/43509809913.pdf
    • https://omomediacion.com/wp-content/plugins/super-forms/uploads/php/files/37820f7d8057ae89e4a47ba387a2009f/numepavobetopatudij.pdf
    • https://www.expoagrogto.com/wp-content/plugins/super-forms/uploads/php/files/l7viqsl9d9i6796qs6q1ndjl11/86335611304.pdf
    • http://mbcasc.net/imgs/file/sigexobumi.pdf
    • http://brmxn.com/userfiles/file/20210610203628_yut98t.pdf
    • http://amexeuro.com/an3_Uploads/file/xunatamizi.pdf
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085f6f727a96.pdf
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bf9b96a82d8---dadigabunanusuzivuv.pdf
    • http://www.tobywells.org/media/fckdir/file/91311126565.pdf
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/57371795413.pdf
    • http://angelojrobles.com/admin_initial_test/userfiles/file/61120182046.pdf
    • http://brandnewgoods.net/userfiles/file/bujofoviravikojoputexe.pdf
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/160b4c5da74c76---dasegivojanizinubezo.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_off0000f95e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF95E 16792 bytes
font_01_sfnt_off00011175.bin
31ab4acbf7b35353a75399847ea12ca8b33aabeb21e6ceb834c7a7be75a8d8bc
pdf-font-stream PDF embedded font (sfnt) at offset 0x11175 11080 bytes
font_02_sfnt_off00012b28.bin
dfb63132ac421b11839f5242ca275e36ea81cabc16984852818d00a1c0d7aa57
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B28 17048 bytes