Malicious PDF — malware analysis report

Static analysis result for SHA-256 f471efdb68815399…

MALICIOUS

PDF

79.3 KB Created: 2021-09-12 11:43:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-02
MD5: 21409c6460b06a7821c62f908b17a22a SHA-1: a9e1f6fb7754a34578ba3b17bf60ac3850988b60 SHA-256: f471efdb68815399f17e5e2be8f08c3bc9cba3e676dacc0483386d5f562fc842
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://coretry.ru/uplcv?utm_term=top+video+downloader+apps PDF link annotation
    • http://dorp.pl/userfiles/files/pudozavas.pdfIn PDF document text
    • https://chokysitohang.com/Uploads/userfiles/files/34387342353.pdfIn PDF document text
    • https://armature.ir/cache/fck_files/file/vibipatamikaropakuwodu.pdfIn PDF document text
    • http://gelinyuanyi.com/upload_fck/file/2021-9-4/20210904024311292119.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///88275411425.pdfIn PDF document text
    • http://thaimassagemodel.com/ckfinder/userfiles/files/56654353296.pdfIn PDF document text
    • https://www.sexualaufklaerung-schule.ch/ck/ckfinder/userfiles/files/30624744488.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613328d13bf67---14358501682.pdfIn PDF document text
    • http://mvdeastudio.it/userfiles/files/mapuviladarukolejigagoxoj.pdfIn PDF document text
    • http://baominhlabors.com/upload/files/67455035049.pdfIn PDF document text
    • http://vikingpaint.com/user_file/file/selulasejib.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/57769022439.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/e2ac7f4f5d341bf73d41f0ce5ef2d5ce/fegeleberigud.pdfIn PDF document text
    • https://jiu-hang.com/upfiles/editor/files/6748539543.pdfIn PDF document text
    • http://iweldbot.com/ckfinder/pho/files/xasororafogutujepo.pdfIn PDF document text
    • http://studiospazioambiente.it/userfiles/files/884051050.pdfIn PDF document text
    • http://freewest.at/jazugida.pdfIn PDF document text
    • https://www.gryf-wet.pl/ckfinder/userfiles/files/gasazozekokisabadoravokit.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613beecae7242---35614815551.pdfIn PDF document text
    • https://tourpon.kr/FileData/ckfinder/files/20210906_B5BC425375BE1DB0.pdfIn PDF document text
    • http://paliukenas.lt/i/File/xujiselanowobamelagi.pdfIn PDF document text
    • http://goldenstarhotel.vn/images/uploads/files/xomeliwagol.pdfIn PDF document text
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fbd6e557bb---84554334989.pdfIn PDF document text
    • https://digiconelectronics.com/media/zefubawaveliru.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_off0000d235.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD235 10400 bytes
SHA-256: 87d490db04af461c5627e8d54b2ab3c6b08511f3f25b7503d18e11dee25bc3c7
font_01_sfnt_off0000e9e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9E4 17588 bytes
SHA-256: e83d63757662b14b9e25b39f0b0f6badd2a2706d9b55e36b4d0c349c0540c831
font_02_sfnt_off00011729.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11729 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1