Malicious PDF — malware analysis report

Static analysis result for SHA-256 874855c553e902f2…

MALICIOUS

PDF

84.7 KB Created: 2021-09-13 22:03:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: a80d118304da0cc7d0dd937765440be0 SHA-1: 6ff2482380a2351f74a37146bbf4df91ca8ada1e SHA-256: 874855c553e902f2c2e5cbd79061f261b0b4944529f0612034d4eff06a7f2474
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress upload storage and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The presence of external URIs and the nature of the links suggest an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://synerhu.ru/uplcv?utm_term=watch+bare+knuckle+fighting+championship+online+free PDF link annotation
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613ee00fae549---29003759552.pdfIn PDF document text
    • https://yourdentist.ro/app/webroot/files/userfiles/files/75008050368.pdfIn PDF document text
    • http://abdon.madteam.net/ckfinder/userfiles/files/59876554633.pdfIn PDF document text
    • https://wildnaturetravel.com/File/dobewadogepo.pdfIn PDF document text
    • http://boston.pl/fck_pliki/file/73125614615.pdfIn PDF document text
    • https://pieseautocomenzi.ro/userfiles/file/puzadadiboka.pdfIn PDF document text
    • https://songhongresort.com/img/files/79197636624.pdfIn PDF document text
    • http://www.stemcellhairclinic.com/files/files/dipisof.pdfIn PDF document text
    • http://mycoapaisyl.com/webimages/files/vitetewug.pdfIn PDF document text
    • https://oilbasaro.com/web/images/ckfinder/files/20210902210850.pdfIn PDF document text
    • https://australiancaravancentre.com.au/application/third_party/ckfinder/userfiles/files/vebuxasid.pdfIn PDF document text
    • http://bekkercoon.ru/ckfinder/userfiles/files/2426964014.pdfIn PDF document text
    • http://ladispensadicampagna.it/uploads/assets/file/nuvap.pdfIn PDF document text
    • http://studiotecnicopinto.it/userfiles/files/12582996816.pdfIn PDF document text
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/370b4c8f63361f4a2e8c0fbb8e84ee99/83574370001.pdfIn PDF document text
    • http://metafelix.it/userfiles/files/xugorinegoxif.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/dewovo.pdfIn PDF document text
    • http://skiflogistics.ru/userfiles/file/kanovatexuwunav.pdfIn PDF document text
    • http://music-saikung.com/ckfinder/userfiles/files/65265564231.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/1613f4f7173d8f---xuvawimiwufewaj.pdfIn PDF document text
    • http://globomax.eu/userfiles/file/74504711320.pdfIn PDF document text
    • https://xedulichhaiphong.vn/images/news/files/80456976022.pdfIn PDF document text
    • http://www.benyowsky.com/resources/files/laxeroxijopinu.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137d17d74985---23223520665.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_off0000e38e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE38E 11252 bytes
SHA-256: 1bbc002b50945337bf21d1fa01734558cfc499e8ad5e7860768361e85e452e4c
font_01_sfnt_off0000fd95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD95 18040 bytes
SHA-256: cf8c8059758ef91e5acaf2d8cc42ee74fd79f80930f67580ef397444761f8bd1
font_02_sfnt_off00012c96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C96 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1