Malicious PDF — malware analysis report

Static analysis result for SHA-256 231fc4fef13a3725…

MALICIOUS

PDF

90.0 KB Created: 2021-09-19 06:33:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 92a026ea3f82708f9621cf6a757e5c8d SHA-1: e7a2644fde8b920ce617fce9c4f6d32eb72e24b8 SHA-256: 231fc4fef13a3725fdc03419570c5a16b66a706d36a571aa1be2f7732f414cab
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and external URIs. The PDF contains numerous links, many pointing to potentially disposable domains, suggesting a link farm or phishing lure. The embedded JavaScript is likely responsible for redirecting users to these external sites, facilitating the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146973f0ffdd---gajepafubo.pdf In PDF document text
    • http://pcwenhua.com/uploadimg/file/1631138005538045112.pdfIn PDF document text
    • https://weddingitaly.jp/images/file/94798134750.pdfIn PDF document text
    • http://doorsatyrau.com/ckfinder/userfiles/files/koveniliwidamizi.pdfIn PDF document text
    • http://tourbusan.net/FileData/ckfinder/files/20210914_01EA4D21A4DFB542.pdfIn PDF document text
    • https://stancijanegrin.com/UserFiles/files/kejafegukeromafa.pdfIn PDF document text
    • https://www.luthier-auxerre.fr/ckfinder/userfiles/files/womutaxodopezasa.pdfIn PDF document text
    • http://poltinka.ru/userfiles/file/63905883272.pdfIn PDF document text
    • http://obrienbuilders.com/userfiles/file/64076232799.pdfIn PDF document text
    • https://dodatnojamstvo.com/userfiles/file/93417059645.pdfIn PDF document text
    • https://guineaservicesproviders.com/gsp/files/padumukusuv.pdfIn PDF document text
    • https://postele-z-masivu.sk/ckfinder/userfiles/files/77599102658.pdfIn PDF document text
    • http://occahomesearch.com/userfiles/files/xigeseturilofemupuxar.pdfIn PDF document text
    • https://4of100churchstreet.com/assets/media/files/26235030073.pdfIn PDF document text
    • http://escrima-rlp.de/userfiles/file/kitafufewaz.pdfIn PDF document text
    • https://konferencii.ru/js/ckfinder/userfiles/files/45606607040.pdfIn PDF document text
    • https://telorgabus.com/contents/files/xetitesafi.pdfIn PDF document text
    • https://tuoitre.bacgiang.gov.vn/lib/ckfinder/files/limuzufuleta.pdfIn PDF document text
    • https://yingzhaoliuart.com/upload/file/87141308420.pdfIn PDF document text
    • https://kasihpaham.com/contents/files/95440664160.pdfIn PDF document text
    • http://eatoceanic.iorderfoods.com/uploads/files/22360944584.pdfIn PDF document text
    • http://bhartiyambeohari.in/userfiles/file/35174482870.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/161395caa42453---gelitelanidavolazomi.pdfIn PDF document text
    • http://ilink.pl/userfiles/file/56266550203.pdfIn PDF document text
    • http://chandravanshi.com/userfiles/file/2202696421.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=keyword+popularity+researchPDF 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_off0000fbb2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBB2 10800 bytes
SHA-256: 20d8be09a675252b55ad9db2c91c02f8df26cce5b4d2e51093939261368a7491
font_01_sfnt_off000114cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114CB 17504 bytes
SHA-256: daa0aaa939b0ab265ed13662f729832695d839c6874e8d5ea07ec83851d972f0
font_02_sfnt_off00014205.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14205 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1