Malicious PDF — malware analysis report

Static analysis result for SHA-256 518a34eb3bcf077d…

MALICIOUS

PDF

71.1 KB Created: 2021-09-07 23:48:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b6f4049ec212e8cf939a8a5a21f6ae36 SHA-1: bd7be43df88d8e143ad5c98e463401217af48746 SHA-256: 518a34eb3bcf077d9bc28137e24cf58629e41ba69e7b2aed5ecfdc130539c09a
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier, with multiple heuristics indicating it functions as a link farm. The embedded URLs point to various domains, some hosted on compromised WordPress sites, suggesting an attempt to lure users to malicious content or phishing pages. The document body is largely unreadable binary data, but the presence of numerous external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly indicate a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://laborke.ru/uplcv?utm_term=hirschmann+spider+4tx%2F1fx+pdf
    • https://akvaguru.hu/user/file/porazotuvejemeferulut.pdf
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/e49f84c132e492c33bd2d708a917db1e/62281246858.pdf
    • http://aquatrustfina.com/userfiles/file/60542432631.pdf
    • http://lws-realestate.com/userfiles/files/dasimidefab.pdf
    • https://teyadegitimvideo.com/calisma2/files/uploads/nuruzoxovibine.pdf
    • http://vladjurnalist.ru/archive/file/posexakitugajadupu.pdf
    • http://namjapizza.com/app/webroot/files/82884512352.pdf
    • http://alphasigmaoverseas.com/userfiles/file/96969110049.pdf
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/bi47nq6gccsn48074fvtpk4f9m/34476176211.pdf
    • http://szao-spb.ru/images/news/file/30446797679.pdf
    • http://dr-onesrl.com/userfiles/files/bapofanuxofabopeguk.pdf
    • http://shop-cartuning.pl/userfiles/file/84738350628.pdf
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/160729bdda8c9b---5764978921.pdf
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/e833cc5939d5687b978ade8c61a54d94/vududirijidubagukib.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bc8636ceb8---ruvoxotidun.pdf
    • http://dxqzx.com/ckfinder/userfiles/files/20210728_100433.pdf
    • http://infosierra.es/images/editor/45914568349.pdf
    • http://belv.ru/userfiles/file/93361716958.pdf
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1610d55f4189bd---zigek.pdf
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/dec2ad737376e2f96083f4a1ffc7432f/1866895195.pdf
    • http://csc-0411.com/userfiles/file/20210608074455_xwsb9r.pdf
    • https://grup-insaat.com/userfiles/file/39327546591.pdf
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608d8941d30c9---dasizotitovebekibarawepug.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_off0000b57e.bin
ed625ef4dfe8b7677719fb597d6125929176d0b190a080af18fc641a70f7a960
pdf-font-stream PDF embedded font (sfnt) at offset 0xB57E 10976 bytes
font_01_sfnt_off0000cee6.bin
9b85333d09694b11077cfd7d9b6c8388324f000c8dc48bb4d1c5d4a681a261c6
pdf-font-stream PDF embedded font (sfnt) at offset 0xCEE6 15576 bytes
font_02_sfnt_off0000f6c8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6C8 16792 bytes