Malicious PDF — malware analysis report

Static analysis result for SHA-256 23be10f51f964e4b…

MALICIOUS

PDF

79.5 KB Created: 2021-09-22 17:25:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5fa9dfddc07ca12234bac6b2b9aceb3b SHA-1: 4d1db944870430a69da25a2ee71c4952ec341438 SHA-256: 23be10f51f964e4b64e7543bff1b6a57121a8fc858e5c4172203ee43f8a57aca
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, with a high concentration of links to distinct hosts, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URIs point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://koreabulk.net/userData/board/file/jerofevi.pdf In PDF document text
    • http://automsystem.com/UploadFile/file/20210910233504328.pdfIn PDF document text
    • http://masan315.net/board/imagefile/file/tujajapodudogavi.pdfIn PDF document text
    • http://www.arborvitae.cz/ckfinder/userfiles/files/nivazozexatutadonefaraz.pdfIn PDF document text
    • http://goodtraefarm.com/ckupload/files/kepozuvopenowok.pdfIn PDF document text
    • http://gearcon-eng.com/file_media/file_image/file/bisabok.pdfIn PDF document text
    • https://dolphinsolutions.net/ckfinder/userfiles/files/xikif.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/7d23c12d2ebcf8988076907ddefaf249/tageguvugilox.pdfIn PDF document text
    • http://hanart21.com/files/userfiles/file/71758834559.pdfIn PDF document text
    • http://skkl.cn/filespath/files/20210910062305.pdfIn PDF document text
    • http://slbreakingnews.com/ckfinder/userfiles/files/xaserizipumasupipujumajud.pdfIn PDF document text
    • http://bgindus.com/t/tutorfirm/uploads/ck/files/xujesimarada.pdfIn PDF document text
    • http://optimumnieruchomosci.pl/uploads/userfiles/files/50299784728.pdfIn PDF document text
    • http://pantipplaza.com/userfiles/file/gefal.pdfIn PDF document text
    • http://uklearningnetwork.com/userfiles/file/67459528623.pdfIn PDF document text
    • http://2222.netsociality.com/upload/files/83657655012.pdfIn PDF document text
    • http://dintainoodle.com/uploads/files/34262301140.pdfIn PDF document text
    • http://dainindo.com/Uploads/userfiles/files/72655644230.pdfIn PDF document text
    • http://stlukesfp.org/ckfinder/userfiles/files/9610831456.pdfIn PDF document text
    • https://avigailpekelman.com/sites/default/files/file/rudiju.pdfIn PDF document text
    • https://palet-school.com/files/files/43948876555.pdfIn PDF document text
    • http://bladensburg.abwingsmd.com/uploads/files/93073245892.pdfIn PDF document text
    • https://happy-playground.gr/uploads/_uploads/files/27876819427.pdfIn PDF document text
    • https://sicurezzaips.it/uploads/file/wifabor.pdfIn PDF document text
    • http://tomboy2.com/images/library/File/binojabosirafuvidugu.pdfIn PDF document text
    • http://bbhshipyard.com/userfiles/file/5752281500.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16134a18e115c6---xugarifimukakoveweji.pdfIn PDF document text
    • https://tasleemdubai.com/userfiles/files/bolokunopavozawuraxuvodi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=hotspot+shield+premium+vpn+apkPDF 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_off0000ceb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEB0 18672 bytes
SHA-256: 79fd0ae594daeaf052ca72e3af6b055a8f57e07bfdd874e7d8cc56e24e50ebc9
font_01_sfnt_off0000feee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEEE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011705.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11705 10904 bytes
SHA-256: 7c3f60797309e4b6c0efe8f45e893fd27cbf11e18918a9db77922b2f7e02a13a