Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae981dc5904aeef8…

MALICIOUS

PDF

79.9 KB Created: 2021-09-10 14:04:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: b05d97caabe519ebb4ef908a50df2472 SHA-1: 80d6a5cbafb3cc11ee9f61d7f4ed76d96ab043ef SHA-256: ae981dc5904aeef86f0291f1092378d343b8e1f735ee8bac1ac3a4b7058865ad
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF file flagged as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs pointing to a link farm, suggesting a phishing or SEO poisoning campaign. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a high likelihood of malicious intent through link manipulation. While no scripts were explicitly extracted, the nature of the embedded URLs and the link farm structure strongly suggests an attempt to redirect users to malicious content or further download stages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://autothudo.vn/upload/fck/file/lumagi.pdf In PDF document text
    • https://peterdegendt.be/file/gipimaleresetejagubuxex.pdfIn PDF document text
    • https://hophamthaibinh.com/upload/files/15508733829.pdfIn PDF document text
    • https://purmoradiatoriai.lt/images/files/tiwatesokepabebixulemuv.pdfIn PDF document text
    • https://marblo.ph/app/webroot/img/files/29714625314.pdfIn PDF document text
    • http://suliaox.com/v15/Upload/file/20219973286691.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16133336d0484a---bipimitolotenivipapaxis.pdfIn PDF document text
    • http://dallard.fr/ressource/site-image/files/vazutidovefade.pdfIn PDF document text
    • http://nguoigiupviec99.com/webroot/img/files/jaxevedozorogelis.pdfIn PDF document text
    • https://goez1.com/10005001208290177/ckfinder/userfiles/files/78575323346.pdfIn PDF document text
    • http://cuanhuadanang.vn/uploads/image/files/paxavomovopobuwa.pdfIn PDF document text
    • https://pezenasenchantee.fr/userfiles/file/bejejisa.pdfIn PDF document text
    • https://szallas-karpatalja.com/upload/79789603392.pdfIn PDF document text
    • http://movietek.vn/hinh-anh/files/momatilorifupotomonebina.pdfIn PDF document text
    • http://xn--42-6kcdlkbomh7beggito5p.xn--p1ai/userfiles/file/32101879345.pdfIn PDF document text
    • http://s-pack.kr/userfiles/file/20210902195011.pdfIn PDF document text
    • http://hzosm.com/images/upload/File/xoxuvakelobikanagejew.pdfIn PDF document text
    • http://vvk-wiedermann.at/userfiles/file/30939869265.pdfIn PDF document text
    • http://xn--hy1bt45apoap01a.net/jangheung/userfiles/file/82189485840.pdfIn PDF document text
    • http://hzbmsj.com/images/upload/File/nosixe.pdfIn PDF document text
    • http://tyros-club.de/userfiles/file/29661908307.pdfIn PDF document text
    • http://lorofilmes.com/Uploads/ckfinder/userfiles/files/jegatewedarusugi.pdfIn PDF document text
    • http://wawa757.com/uploads/files/51853504431.pdfIn PDF document text
    • http://nscenter.cn/upload/files/61602661400.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=game+booster+60fps+androidPDF 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_off0000d473.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD473 17032 bytes
SHA-256: fd8ac20cf736b8127241601577803b8928678b470fa053b7b5c8aa337744080e
font_01_sfnt_off000100c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000118dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118DC 11084 bytes
SHA-256: 256025788ebb170b903b4900fdd88f7ff337d2e793f7d63a36778aa36667aa66