Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5a3665c62817762…

MALICIOUS

PDF

70.1 KB Created: 2021-09-09 11:14:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 18ee501addd191c8dec1bd4bc30bd613 SHA-1: 9fff80d62ab93c0d16c2f0a93cb8e41d8e1a7bf9 SHA-256: d5a3665c62817762d991b3669081bcb8e33f8613e0096dfc19a9c4e907c17a6a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm pointing to numerous external PDF files. The presence of embedded URLs and the nature of the heuristics suggest this PDF is part of a phishing or malware distribution campaign, likely delivered as a spearphishing attachment. No scripts were extracted, but the overall structure points to a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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://budoprojekt.eu/obrazy/file/wupafokox.pdf In PDF document text
    • http://onyx-innovations.com/assets/ckfinder/userfiles/files/7384253169.pdfIn PDF document text
    • https://olterus.com/contents/files/duwepufezugeworapav.pdfIn PDF document text
    • http://oio.cn/uploadfiles/files/duxadenokaj.pdfIn PDF document text
    • http://denis-lefebvre-services.com/fichiers/file/rimosuluwopegonelux.pdfIn PDF document text
    • http://kulturazebrak.cz/userfiles/zalalalozuxutur.pdfIn PDF document text
    • http://sibaco.ru/ckfinder/userfiles/files/28914505990.pdfIn PDF document text
    • http://dkyangmei.com/uploadfile/file/2021090618282873499.pdfIn PDF document text
    • https://bodymason.com/user_uploads/files/35077032617.pdfIn PDF document text
    • http://efuegypt.org/userfiles/file/57068617423.pdfIn PDF document text
    • https://dmitrovka-zn.ru/admin/ckfinder/userfiles/files/26807273970.pdfIn PDF document text
    • http://bdnchem.com/upload/files/69861395209.pdfIn PDF document text
    • http://murzilka.biz/images/uploads/file/67657899142.pdfIn PDF document text
    • https://www.natursany.com/ckfinder/userfiles/files/72116645321.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/161370d8492487---naxezerutulikirized.pdfIn PDF document text
    • http://lexxyin.net/files/fckeditor/file/kerarapibusujodelafotep.pdfIn PDF document text
    • http://auburn-properties.com/userfiles/files/moxajokefutotodozowewese.pdfIn PDF document text
    • http://sherwoodchambergolf.org/ckfinder/userfiles/files/kokakalejiwomorelid.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/16136ddafbeb58---fotewotesebutebarekajelu.pdfIn PDF document text
    • http://rezidencianestor.sk/app/webroot/files/ckeditor/files/13020132798.pdfIn PDF document text
    • http://weforyou.it/userfiles/files/52842301160.pdfIn PDF document text
    • http://koala-al.com/d/files/dexogex.pdfIn PDF document text
    • https://datenglagi.com/contents/files/9403936453.pdfIn PDF document text
    • https://mariellatriolo.it/public/file/padawerikixaw.pdfIn PDF document text
    • http://bilmatbasim.com/userfiles/file/tezepofamatolutakugemide.pdfIn PDF document text
    • https://hiddencliff.kr/FileData/ckfinder/files/20210909_0A22BBEAFACD51E5.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=mx+player+tamil+movies+2020PDF 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_off0000b2df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2DF 15348 bytes
SHA-256: 8d76560b6a7d9f3b3bc9a8e3ffabb7fb54829bd5dbabc4a7895e16d8fc5ac7e0
font_01_sfnt_off0000d9c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9C7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f1de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1DE 10828 bytes
SHA-256: dcec965fb1a2302c14155952f5a55ed72951cea2ee2dc22df4e4c6006d080dbc