Malicious PDF — malware analysis report

Static analysis result for SHA-256 5557aafc0453cf19…

MALICIOUS

PDF

86.0 KB Created: 2021-06-25 20:08:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 26214a181e2c1b8efd41747bb3f58f8c SHA-1: 89fd6ee5dbbf12724853aa6753a17841add27ab8 SHA-256: 5557aafc0453cf194614099b2918eaa92c46bd603abdbfd6255155efdfdc9129
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV detecting it as a phishing trojan. It contains numerous external links, many pointing to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, but the presence of external links indicates an attempt to lead the user away from the current document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://cructi.ru/uplcv?utm_term=torchlight+2+guts+download
    • http://hnc2.com/userfiles/file/79474535060.pdf
    • http://antifftech.com/uploadfile/file///2021062021251383.pdf
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1608b2a93ae86a---dasezagir.pdf
    • http://basaritarim.net/admin/editor_resim/file/vagiwazazuna.pdf
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160720cc478af3---71221534373.pdf
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/1f8a78693bf4b2f873e4205573f7a582/72148631065.pdf
    • http://falerisztika.hu/tmp/4907443800.pdf
    • http://xn--vb0b83rba554gca.kr/page_data/file/20210507112552.pdf
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aac5dae6e1a---nixefi.pdf
    • https://apz-arte.com/ckfinder/userfiles/files/boxib.pdf
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/ac218f79e1a558d1d90b5faef4d974b9/nefarazilodowisupodax.pdf
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160870371c4cb7---lodazitonadigojubumas.pdf
    • https://afayl.com/userfiles/file/31901455139.pdf
    • https://dacinsara.ro/fckfiles/file/89511042326.pdf
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc2a8cca6d---lokizigarozozobuxoberuwe.pdf
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a5e70d01bcb---30631688882.pdf
    • https://www.chesapeake-lighting.com/wp-content/plugins/super-forms/uploads/php/files/8c07face582260c03d44814598539693/tujelanujeratemanadepiwob.pdf
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1f64a46344---294576047.pdf
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/7a7sq61mf32nl9i7d90ir7bgl2/gumezanixorefas.pdf
    • https://mziagroup.com/wp-content/plugins/super-forms/uploads/php/files/pcecsuuv5mov2sq1b5gnkj2pqt/medurobifopawatevagewiz.pdf
    • http://4bx.pl/public/file/sufutitigazojabisa.pdf
    • http://xn--h49al33a2zdp0eo1x.com/DATA/file/20210521193352.pdf
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609d37c0b032a---dowidazotavekazofudiso.pdf
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/16075f56c6cfc2---39856388552.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_off0000edb1.bin
3ba2c11c4c5852f6b3b8397fffb47081579d59a842227a27e1125765cafb73d5
pdf-font-stream PDF embedded font (sfnt) at offset 0xEDB1 16920 bytes
font_01_sfnt_off00011a1a.bin
63721376359e072610c75cfa720f7c6fd7a84dffcb27bf5ea4dff270a6ddfdbb
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A1A 10788 bytes
font_02_sfnt_off000132d4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x132D4 16792 bytes