Malicious PDF — malware analysis report

Static analysis result for SHA-256 581e3687f6ead16b…

MALICIOUS

PDF

75.8 KB Created: 2021-09-17 01:25:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 50d67604499ef63ce8da88a264753248 SHA-1: d0fc653add6687342929774c267534fd9b85b3ee SHA-256: 581e3687f6ead16b58059662a4d190d2a414ee0bb0a84e104e31491cca6a5029
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristic analysis revealed it functions as a link farm, containing numerous external URIs pointing to other PDF files hosted on various domains. This suggests a tactic to distribute malicious content or manipulate search engine results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 5

  • 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.
  • 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://yigang-lin.com/uploads/files/202109030033584103.pdf In PDF document text
    • http://uptownfallschurch.com/uploads/files/rosudazawusujivakudobax.pdfIn PDF document text
    • http://neuchina.org/userfiles/file/dunuxijagezat.pdfIn PDF document text
    • https://incoyun.com/calisma2/files/uploads/zarosewabixedaledorikuwo.pdfIn PDF document text
    • https://togelunited4d.com/contents/files/fegumezukasepanobunutalod.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f9e3870a04---padul.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/62838061244.pdfIn PDF document text
    • http://phutungquanghieu.com/app/webroot/files/ckfinder/files/59450429162.pdfIn PDF document text
    • http://crosswaysrecruitment.com/userfiles/file/bulemoxa.pdfIn PDF document text
    • http://gearonlaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vovuvas.pdfIn PDF document text
    • http://impressivetravelvietnam.com/upload/files/zavozokov.pdfIn PDF document text
    • http://dautuck.com/uploads/userfiles/file/45191135406.pdfIn PDF document text
    • http://africareview.in/userfiles/file/58568866812.pdfIn PDF document text
    • https://www.akilciilacdernegi.com/ckfinder/userfiles/files/velenamovudagebaxamilizes.pdfIn PDF document text
    • http://fsnmmaterials.com/UPFILE/userfiles/files/bunirenuso.pdfIn PDF document text
    • https://pasarangroup2.com/contents/files/vifadiseguwi.pdfIn PDF document text
    • http://superfishinglewood.com/uploads/files/58972852248.pdfIn PDF document text
    • https://brtim.com/uploads/wysiwyg/files/nidinufexuzof.pdfIn PDF document text
    • https://saint-florentin.charcutier-traiteur.fr/ckfinder/userfiles/files/64434334639.pdfIn PDF document text
    • http://thucphamchucnangmy.vn/uploads/files/18494449871.pdfIn PDF document text
    • http://ambcavallon.eu/userfiles/files/2224011377.pdfIn PDF document text
    • https://sts-cct.com/app/webroot/userfiles/files/mosisatusevezimiw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=quantum+mechanics+griffiths+3rd+edition+pdfPDF 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_off0000c1cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1CF 17576 bytes
SHA-256: cef035dcd6f5a9a2644f601238e790584015814311065780d84a07331ce8c571
font_01_sfnt_off0000ef27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF27 11352 bytes
SHA-256: 0497ca88ee4d30d25188acd8dc3e1b83f5cf5909813b06199a2f92d95cb50230
font_02_sfnt_off0001099a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1099A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1