Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8ab359720e90508…

MALICIOUS

PDF

90.3 KB Created: 2021-09-24 11:58:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 0e4d00c421fcb9ecb80d11f42de22d52 SHA-1: 6960a5320ade7b81ab1373b64daa21a109ff99af SHA-256: a8ab359720e905082a14d1894667c706608b75bcdc35f3b52c8dbc3f58e214f9
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. The PDF contains numerous embedded URLs pointing to external domains, many of which are structured as link farms. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior, suggesting the PDF is designed to redirect users to potentially harmful content. The presence of multiple external URIs further supports this attack pattern.

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://pixomot.ru/uplcv?utm_term=all+for+the+game+nora+sakavic+pdf PDF link annotation
    • http://visusmarble.com/images_upload/files/65693613902.pdfIn PDF document text
    • https://iwanbim.iwan.co/userfiles/files/fewowojema.pdfIn PDF document text
    • http://okun.su/upload/file/rikanagizeb.pdfIn PDF document text
    • https://apotekatia.ba/fajlovi/mexopo.pdfIn PDF document text
    • http://kadh.kr/bobod/upload/file/5568274750.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/dupojenewiz.pdfIn PDF document text
    • http://av-jet.ru/userfiles/file/vewodinomasukebitosarobu.pdfIn PDF document text
    • http://babijie.com/upload_fck/file/2021-9-6/20210906072150396720.pdfIn PDF document text
    • http://keemunblacktea.cn/uploads/file/110316343384.pdfIn PDF document text
    • http://skonasystems.com/userfiles/file/fabekemegukesavu.pdfIn PDF document text
    • https://insolite.lu/img/userfiles/files/65938070268.pdfIn PDF document text
    • https://resttour.com/images/userfiles/files/jejaxi.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/85a112b4cdff619384a20d74e0846395/nuwob.pdfIn PDF document text
    • http://studiopignotti.it/userfiles/files/bojavutawazu.pdfIn PDF document text
    • http://tiendanatacion.com/noticias/files/zigetuvana.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/2021991125541622.pdfIn PDF document text
    • http://christopherspubandgrille.com/userfiles/files/95887239113.pdfIn PDF document text
    • http://topoint.net/userfiles/fckFile/20210918143704.pdfIn PDF document text
    • https://traiteur-troyes-mariage-buffet-aube-10.blaisot-traiteur.fr/ckfinder/userfiles/files/gagusitixuzenaporaxupoli.pdfIn PDF document text
    • http://hicoweld.com/shop/fck_file/file/39122358457.pdfIn PDF document text
    • http://ottotech.center/userfiles/file/poxefufoliwawureditamider.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138e2e9a4720---gefaxogefukasuk.pdfIn PDF document text
    • http://chayka-svg.ru/files/42033700819.pdfIn PDF document text
    • http://ardeche.proximeo.com/ckfinder/userfiles/files/tevelarizivibewokadebe.pdfIn PDF document text
    • https://bokaichenyu.com/upload/files/tilezimugojenafukilod.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_off0000f995.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF995 18300 bytes
SHA-256: f466e47d5a566c02907f1f9bfc86d70a91cc3922565bc33f0afb9871084783a6
font_01_sfnt_off00012964.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12964 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001417b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1417B 11204 bytes
SHA-256: 61ded82a822bc92c93a00c497a69d643946b56e55867f98cb63b7342bf1af932