Malicious PDF — malware analysis report

Static analysis result for SHA-256 6d8821845a8e49cf…

MALICIOUS

PDF

178.7 KB Created: 2021-09-17 03:59:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 054f5149529510fbd0a7630fe88fa720 SHA-1: 7b0a8d0357c44e6e8ca862dee5c94c9fe70b3161 SHA-256: 6d8821845a8e49cf84792d2cf26a34f3f32284e0e81d072de75ea78a272c1f89
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, indicating a link farm designed to lure users to malicious content. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this malicious intent. The ML classifier and ClamAV detection further confirm its malicious nature.

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://synerhu.ru/uplcv?utm_term=felder+principios+elementales+de+los+procesos+quimicos+pdf PDF link annotation
    • https://energooptima.hu/upload/File/77201732056.pdfIn PDF document text
    • http://njxinbell.com/upload/files/sikevuw.pdfIn PDF document text
    • http://uitvaartverzorgingsindex.nl/images/uploads/86133350519.pdfIn PDF document text
    • http://mrukseo.pl/userfiles/file/67060558712.pdfIn PDF document text
    • https://maritime-models.com/userfiles/file/pumilikegorawafal.pdfIn PDF document text
    • https://vicareyou.com/userfiles/file/sikukewokosilud.pdfIn PDF document text
    • https://dananeye.com/uploads/files/202109152057305207.pdfIn PDF document text
    • http://cuakeobinhduong.com/upload/files/97261199944.pdfIn PDF document text
    • https://hoangnhataudio.vn/media/files/wujutimekutibebokunik.pdfIn PDF document text
    • https://shevian.com/images/file/sakubip.pdfIn PDF document text
    • http://cwpni.com/userData/ebizro_board/file/narab.pdfIn PDF document text
    • http://nfrostov.ru/upload/files/bipurimasefamixezi.pdfIn PDF document text
    • http://solamsys.com/userData/board/file/lozudodalesozemaze.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137b5474edbb---misudafediso.pdfIn PDF document text
    • https://cleartunemonitors.com/ckfinder/userfiles/files/59184127362.pdfIn PDF document text
    • http://lltsg.com/uploadfile/file///2021090208453384.pdfIn PDF document text
    • http://pilanatofishing.com/home/sandbox/domains/shelter.sandbox.tritek.hk/public_html/ckfinder/userfiles/files/83488641765.pdfIn PDF document text
    • http://gemmacapitalgroup.com/foto/file/fixejiguwepejoragasez.pdfIn PDF document text
    • http://sb-78.ru/files/file/mibizomakewupetem.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/5a276dfe0f027d253f0c557c0ae8f7df/videmokaro.pdfIn PDF document text
    • http://kelvista.lt/images/files/kasulilibesuwelebipelizuw.pdfIn PDF document text
    • https://laatuwhuisweerstralen.nl/upload/file/nutafatono.pdfIn PDF document text
    • http://artiguardia.pl/userfiles/file/15321246201.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161367578b7e88---serogodisufebegimam.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0002506c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2506C 11004 bytes
SHA-256: 4a8271b5f34edd5d0ba93117dcf2c1ce646cbc7888115d6c59edb3d55fc7c898
font_01_sfnt_off000269b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x269B5 22872 bytes
SHA-256: f2b6a7fd67ae29bf021e3b7fb6f0771600c188879990ebeb81ec3d60eecf4ab8
font_02_sfnt_off0002a3ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2A3EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1