Malicious PDF — malware analysis report

Static analysis result for SHA-256 4834ba2ac2d4b9d8…

MALICIOUS

PDF

76.0 KB Created: 2021-09-07 06:57:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 80cbbaff26d062b34bde87258cb5914c SHA-1: 0ee9deda1a72fd5096cb6a8f0f72c67327853833 SHA-256: 4834ba2ac2d4b9d89fbb4bcab77e4f030fbc05a005584f74733857df9a6b9448
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, a common technique for executing malicious code within PDFs. It also features a link farm pointing to multiple distinct hosts, many of which are hosted on compromised WordPress sites or disposable domains, suggesting an attempt to obscure the final destination or leverage compromised infrastructure. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://kino-cosmic.ru/sadm_files/tubotobiminefifiza.pdf In PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/46c12414b26c01897e244322dde4c750/lesekipujilokudiliwa.pdfIn PDF document text
    • https://amitadevnani.com/userfiles/file/79382763722.pdfIn PDF document text
    • http://studioarchperissinotto.eu/userfiles/files/33085819830.pdfIn PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160714fc3712b4---maxejezefezefeserew.pdfIn PDF document text
    • http://pvvc.cz/files/32579265831.pdfIn PDF document text
    • https://rubyyadav.com/nbloom/fckuploads/file/zexerabowojobasefejik.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/adjbg6dasjkmk4un6bgt4430s2/zolesukejupijemixixila.pdfIn PDF document text
    • https://silky.ae/images/bulk_images/files/bebenikemitume.pdfIn PDF document text
    • http://freetds.net/userfiles/file/75192604927.pdfIn PDF document text
    • http://asirakademi.com/resimler/files/wetumefotazadajesebibuxi.pdfIn PDF document text
    • https://www.shamshabaddiocese.org/files/js/ckfinder/userfiles/files/zakukexorofivebaditezeje.pdfIn PDF document text
    • http://tcmoving4cure.com/clients/a/a2/a295acc0500fd37d831de80ba00a7552/File/12596159600.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/565e8c0ad225f1244d197216335f9f50/41453295006.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/74e364c51aa42997c4600855fdd8a848/73019266244.pdfIn PDF document text
    • http://paintmaster.hu/js/ckfinder/userfiles/files/mavulegoteba.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/f1ae962ab4a2df020af19564d9732679/87327150605.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/99344771467.pdfIn PDF document text
    • http://epoch-making.jp/js/upload/files/67692416334.pdfIn PDF document text
    • http://bjjiffy.com/upload/ranuwugopinuvujonekiko.pdfIn PDF document text
    • http://irinka.org/ckfinder/userfiles/files/26244077360.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612dc2495c0c7---gafovuderafilegawena.pdfIn PDF document text
    • https://speak82.com/_UploadFile/Images/file/zovarodus.pdfIn PDF document text
    • https://metricgroup.it/uploads/file/65558015418.pdfIn PDF document text
    • https://csn-alliance.com/data/files/bukewatupezagu.pdfIn PDF document text
    • https://wheelmartthailand.com/image/upload/File/wabeluposowefuxumipado.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=climate+zones+on+earth+worksheetPDF link annotation
    • 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_off0000c78c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC78C 16584 bytes
SHA-256: 9362938843c3b16dadae81b8a21883671f17f615a8896612e95bd2f96d8176f1
font_01_sfnt_off0000f263.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF263 10640 bytes
SHA-256: d2897305c933b67cf8d867ea0b23981fc2a2f259de1277f768e62e35f164b2f1
font_02_sfnt_off00010aab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AAB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1