Malicious PDF — malware analysis report

Static analysis result for SHA-256 04a8f1e3e4aa022c…

MALICIOUS

PDF

88.4 KB Created: 2021-09-16 10:17:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 56120f5169a6cbf72ba41df23e31041c SHA-1: 09218304b748c793c214b60dc2b610401a99241a SHA-256: 04a8f1e3e4aa022cd318581b7c6ff95bf8620c9376d271dbff9e7f965ad6f464
156 Risk Score

Malware Insights

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

The PDF document contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, forming a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. The primary function appears to be redirecting users through a series of links to ultimately reach a malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://coretry.ru/uplcv?utm_term=grave+defense+apk PDF link annotation
    • http://prosefkuchare.cz/userfiles/85495953619.pdfIn PDF document text
    • https://atavio.ru/files/file/54375435836.pdfIn PDF document text
    • http://tensoinox.com/userfiles/files/fazavepiputuwijifep.pdfIn PDF document text
    • http://terralis.eu/catalogue_dynamique/file/79041631258.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1613e5532002cf---kofimetovedopirewalonutor.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/161410b0c52e97---68008249072.pdfIn PDF document text
    • http://aotwresort.org/ckfinder/userfiles/files/59898398555.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614129d5cf83f---nomapofasurab.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fcbeb70db7---47431464198.pdfIn PDF document text
    • https://anitacalderon.com/ckfinder/userfiles/files/zomirola.pdfIn PDF document text
    • https://alariel.be/userfiles/file/45596517437.pdfIn PDF document text
    • https://angel-juicer.com/FileData/ckfinder/files/20210905_048F42674F094A6E.pdfIn PDF document text
    • https://bikidi.com/UpFiles/WebEditorFiles/file/balotexi.pdfIn PDF document text
    • http://maytinhtuyenquang.com/home/maytinhtuy/domains/maytinhtuyenquang.com/public_html/images/file/putenelak.pdfIn PDF document text
    • https://middletonchambers.com/ckfinder/userfiles/files/ravite.pdfIn PDF document text
    • http://myshopgroup.com/userfiles/files/48035506937.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/jvp53fadb5ga60tohekm8ra979/vogitotaxez.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/e1797de547c28c49c190e535c8603f55/definokatikepo.pdfIn PDF document text
    • http://fireprovietnam.net/luutru/files/94761976770.pdfIn PDF document text
    • http://5lovestartw.com/CKEdit/upload/files/34009856736.pdfIn PDF document text
    • https://geelaboba.dswip.com/ci/userfiles/files/bubaninafudodafaxopiborag.pdfIn PDF document text
    • http://chatyzvule.cz/uploads/67775136692.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613aba3d1ab53---pajinufapumuneremijotulus.pdfIn PDF document text
    • https://s-serviss.lv/userfiles/file/9252353978.pdfIn PDF document text
    • http://hyosangjo.com/userfiles/file/20210908205048.pdfIn PDF document text
    • https://ukmriptek.org/codeIgniter-hmvc/userfiles/files/42685031315.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_off0000f5f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5F4 18024 bytes
SHA-256: 233c175518623532686819f6cfea4c822df80ca1275871f06ba511745ff0b492
font_01_sfnt_off000124c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124C4 10332 bytes
SHA-256: 1a60a8e6ba83075e75a18717f8a0541d8e64cbf66f840a417b0a36fac893bdda
font_02_sfnt_off00013c39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C39 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1