Malicious PDF — malware analysis report

Static analysis result for SHA-256 e88245f9d0a8c4b3…

MALICIOUS

PDF

83.1 KB Created: 2021-09-18 10:04:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 1880b2ba20a955f65602e0a24069b857 SHA-1: 89b959592a5df4bc10a8987cb75e113b4048d59b SHA-256: e88245f9d0a8c4b3c3b4a1d4c41f76d7a763b8bee046490bafe55e694fdddac2
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. The PDF also includes numerous external URIs, many of which point to PDF files on various domains, suggesting a link farm or redirection mechanism. The embedded JavaScript likely facilitates the redirection to these external sites, potentially for phishing or to download further malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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
  • 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://xn--brneneskontor-landsforening-b0c.dk/userfiles/file/wagemajewubafufuvijo.pdf In PDF document text
    • http://ahlhy.com/uploads/file/101046293276.pdfIn PDF document text
    • https://grupo.iberia.es/js/ckfinder/userfiles/files/lefapisifetamonufojiwit.pdfIn PDF document text
    • http://vtaky.sk/media/file/gewegujezagupu.pdfIn PDF document text
    • http://domgr11.ru/uploads/files/99161062179.pdfIn PDF document text
    • http://kolbiko.com/images/uploads/file/22786301181.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161346321e1c7a---43964234610.pdfIn PDF document text
    • https://ntiverification.com/userfiles/file/42097469040.pdfIn PDF document text
    • https://raguvosbaldai.manovonia.lt/images/files/sadigiwojexe.pdfIn PDF document text
    • http://lishasurgical.in/ckeditor/ckfinder/userfiles/files/6716929114.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142375bbc88d---34315577916.pdfIn PDF document text
    • https://xylemleads.com/userfiles/file/51023976915.pdfIn PDF document text
    • https://beeshark.ro/app/webroot/files/userfiles/files/niditopevenovi.pdfIn PDF document text
    • http://cancercareresearch.com/userfiles/file/43519473842.pdfIn PDF document text
    • http://frutapacargentina.com/ckfinder/userfiles/files/80320355167.pdfIn PDF document text
    • http://apexibd.com/uploads/fck_uploads/file/rosikipaxomefelevefed.pdfIn PDF document text
    • http://upsshop.ru/ckfinder/userfiles/files/59521297427.pdfIn PDF document text
    • http://pobierzplik.pl/uploads/files/vuwamojusamive.pdfIn PDF document text
    • http://vekosgroup.ru/userfiles/file/17370944924.pdfIn PDF document text
    • http://belloverde.net/emailer/file/25519898336.pdfIn PDF document text
    • http://0985028898.kad.tw/kads/ckfinder/userfiles/files/6231641325.pdfIn PDF document text
    • http://elfuklid.cz/foto/Image/file/bapubegubagijamuk.pdfIn PDF document text
    • http://dwallacelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/tuvamezufagaloka.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=6+letter+words+starting+with+cePDF 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_off0000e056.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE056 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f86d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF86D 10804 bytes
SHA-256: 028c1f5e115fb0a22e278586517fb2098ead6dbdf20846ed079cc90c2fe1dec2
font_02_sfnt_off0001111e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1111E 17676 bytes
SHA-256: 973305f94fb08f29609fdf41aeb01fd3fb955ae6635b543849b92f8ea3e54036