Malicious PDF — malware analysis report

Static analysis result for SHA-256 99b731d1477a9e40…

MALICIOUS

PDF

72.8 KB Created: 2021-09-20 23:16:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5cbd780c011e49e7e6b881a45432ee17 SHA-1: ab59cf0aae7b4de7922bdacf3ee9ecd5d23692f1 SHA-256: 99b731d1477a9e40541326d85c461d6f0216b47581c54e0c92ae01061ea3b93a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV detecting it as a phishing trojan. The document contains a link farm pointing to numerous domains, many of which are hosted on compromised WordPress sites or disposable hosting. These links likely serve as redirects to phishing pages or malware download sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://laborke.ru/uplcv?utm_term=game+booster+x+free PDF link annotation
    • http://indyskischool.com/ckfinder/userfiles/files/kokawike.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/ade27e2b7e6f79f067ac77503d550ec1/60882367824.pdfIn PDF document text
    • http://lor-rostov.su/userfiles/files/dolinulalotuvas.pdfIn PDF document text
    • http://crocepadrekolbe.it/userfiles/files/nojaxufelemafapezi.pdfIn PDF document text
    • http://cesnek-vysocina.cz/UserFiles/File/53914618336.pdfIn PDF document text
    • http://vinabomi.com/uploads/userfiles/file/wojatumufexewer.pdfIn PDF document text
    • https://jobtiara.com/files/files/49823118959.pdfIn PDF document text
    • https://terracetemayonetim.com/upload/ckfinder/files/tufusetenujesujimazolepu.pdfIn PDF document text
    • http://progetec.org/userfiles/files/87978223978.pdfIn PDF document text
    • https://yarpaket.ru/userfiles/file/4281134063.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/uemddigc63a0969t1e4ibn65de/kiwajeborizojanotuxeje.pdfIn PDF document text
    • http://toyotarent.kr/FileData/ckfinder/files/20210907_788A69B1519B6419.pdfIn PDF document text
    • http://dispensapertutti.com/userfiles/files/23266759388.pdfIn PDF document text
    • http://asremajazi.com/uploads/files/mazubemipinuva.pdfIn PDF document text
    • https://pfollowers.com/ci/userfiles/files/dujokofafobimotunejar.pdfIn PDF document text
    • http://childconnect.com/swi/fckfiles/file/31684531740.pdfIn PDF document text
    • http://www.blueoak.fr/image/file/21196724998.pdfIn PDF document text
    • http://xn--80aamwn.xn--p1ai/userfiles/file/98179261182.pdfIn PDF document text
    • http://kingsbrite.com/kingsbrite.com/userfiles/file/37963423009.pdfIn PDF document text
    • http://drivescuolaguida.it/userfiles/files/fexaramafupud.pdfIn PDF document text
    • https://istanajp2.com/contents/files/46894885813.pdfIn PDF document text
    • http://gift-founder.com/archive/upload/files/bazino.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/703bba55aba254d69e916feb1121e355/54575331768.pdfIn PDF document text
    • http://www.farmaciabergua.com/userfiles/files/71105537173.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_off0000bb6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB6B 10412 bytes
SHA-256: fcae3331eec65606630c3399caf34bc9d65966de0252c75eb8b396abfbbaf8f2
font_01_sfnt_off0000d31c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD31C 16392 bytes
SHA-256: 5f90bd10c3e0fffb34ee83d3c9c4503b1fe21b1b222176b67df63fe2b458c248
font_02_sfnt_off0000fd8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD8C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1