Malicious PDF — malware analysis report

Static analysis result for SHA-256 638b6a1512acb50c…

MALICIOUS

PDF

76.5 KB Created: 2021-09-18 00:56:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 08e8e14b3b0cf972115dfae32af73a20 SHA-1: 9d7c4e5643517b9705a428e846bf07e1f5f7d377 SHA-256: 638b6a1512acb50c1c44dc62f508e58ba752e904bb474c160431aa6f009d7fb3
126 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and is identified as a link farm on disposable hosting, suggesting it's used to redirect users to potentially harmful sites. The PDF structure and embedded URLs point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://medvor.ru/uplcv?utm_term=ac+market+old+version+2017 PDF link annotation
    • http://szolnokepul.hu/userfiles/file/wizalefidasaxu.pdfIn PDF document text
    • https://sofahatinh.com/upload/files/zerusujuvejodo.pdfIn PDF document text
    • https://kluchar.net/klucharnet/images/file/74147400124.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/6frr7m66hrg4eaeq5h8l00dqm0/80970660950.pdfIn PDF document text
    • http://chafewyuok.handysociality.com/upload/files/89923061416.pdfIn PDF document text
    • http://numere-mopede.ro/mm/file/16153461095.pdfIn PDF document text
    • http://kapsalonvogue.nl/files/file/jolemitesuzetejozikex.pdfIn PDF document text
    • https://0900107678.com/upload/file/xulew.pdfIn PDF document text
    • http://daiwavn.com/uploads/image/files/felidav.pdfIn PDF document text
    • https://egokituz.eus/files/galeria/files/91565501535.pdfIn PDF document text
    • https://tepihtrava.rs/files/donaga.pdfIn PDF document text
    • https://lederstuhlshop.de/ckfinder/userfiles/files/853219511.pdfIn PDF document text
    • http://businessdevelopmentcenter.pl/uploads/userfiles/files/65671928787.pdfIn PDF document text
    • http://essiac.cz/UserFiles/file/75989065956.pdfIn PDF document text
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f5af25b3bd---roguzajagalat.pdfIn PDF document text
    • http://orosweb.hu/userfiles/file/ramirunosegevugota.pdfIn PDF document text
    • http://ttlh.vn/storage/ckfinder/files/lubifununukukutoloju.pdfIn PDF document text
    • http://amidoux-peintures.com/ckfinder/userfiles/files/64591604113.pdfIn PDF document text
    • http://pnc21.com/files/fckeditor/file/20687197613609bf0a4dc.pdfIn PDF document text
    • http://chekeeh.ir/basefile/chekeehir/files/41797375348.pdfIn PDF document text
    • http://maysoi.com/hinhanh_fckeditor/file/28994151111.pdfIn PDF document text
    • https://francois-daulte.com/ckfinder/userfiles/files/21162535396.pdfIn PDF document text
    • http://phukientubepxinh.info/gomsu/sanpham/anh/files/40360045856.pdfIn PDF document text
    • http://criollo-cocoa.com/userfiles/file/3991734525.pdfIn PDF document text
    • http://velocimapper.com/webfiles/file/93591529253.pdfIn PDF document text
    • 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_off0000c4f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4F9 17680 bytes
SHA-256: 1a09e230a6f30c08971907fa12be2ba70b69da9ce7738c12f595315ebe18474f
font_01_sfnt_off0000f282.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF282 11012 bytes
SHA-256: 866861473630e2b05f1d8f8cfac2cb1826d55db38a891096b42d1eb8368e1a61
font_02_sfnt_off00010c44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C44 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1