Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7a958dbde0828e8…

MALICIOUS

PDF

77.7 KB Created: 2021-09-08 18:26:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5139c982276e0aea84c343af21e57a63 SHA-1: aa90127df84cbd8c4a4e580b7b8b18721a2b2080 SHA-256: a7a958dbde0828e8207552fb3040ac53a6017f65bbcb696aa895d35143bae273
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. It contains numerous links, many pointing to compromised WordPress sites and disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of these links indicates an attempt to lure users to external sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/16131acef7cc2d---4939518491.pdf In PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/ed76c54518babc5c68480654331393db/21133199401.pdfIn PDF document text
    • https://theatresaucinema.fr/uploads/file/saxiketibu.pdfIn PDF document text
    • http://nineslash.com/user_file/file/rozoravuvarediv.pdfIn PDF document text
    • https://warungmimpishio2.com/contents/files/pakarimulo.pdfIn PDF document text
    • https://shiprapublication.com/uniformkontakt/userfiles/image/files/tefapixogutujixubo.pdfIn PDF document text
    • http://colegiosantarosa.com/uploads/imagem/file/42574418748.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/bfc5b6467c39c4222718cbeee1ecd9db/varuzozejirutiza.pdfIn PDF document text
    • https://saintarseny.ca/sites/saintarseny.ca/files/file/wapire.pdfIn PDF document text
    • https://yumasri.com/assets/ckfinder/userfiles/files/kakakamuki.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/b79bce6bee37f5352604c7fa70d09c3d/zerafe.pdfIn PDF document text
    • http://agilesolutions.in/uploads/9847921761.pdfIn PDF document text
    • https://begili.com/uploads/image/files/zimavepa.pdfIn PDF document text
    • http://sumosushingrill.com/uploads/files/kitadiwos.pdfIn PDF document text
    • http://lifeisartfoundation.org/sites/default/files/images/userfiles/file/7559318785.pdfIn PDF document text
    • http://80tner.friend-match.com/upload/files/40868824968.pdfIn PDF document text
    • http://xn--80aaaghhaztbcd1agjgbccsgfftf.xn--p1ai/pict/file/36276883372.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/dk0tjd80kg1qjgstmm2d1a36j2/68918524054.pdfIn PDF document text
    • http://bsa-billiard.by/images_from_html_editor/file/58257529844.pdfIn PDF document text
    • http://a-aqua.fr/ressource/site-image/files/22213643326.pdfIn PDF document text
    • http://fqcycpa.com/jingkelun/userfiles/files/20210903093316.pdfIn PDF document text
    • http://shinaval.ru/userfiles/file/84870775485.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=hafler+ta1100+service+manualPDF 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_off0000cad9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAD9 17640 bytes
SHA-256: 6a5f34f8e93af36e624934adba75a7531a7f1133193deb4eb6e79f4557eef8ff
font_01_sfnt_off0000f8de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8DE 10708 bytes
SHA-256: 15e792fd8e41fed66d7e9e7264a943247ac2c86d6af62c8f7ecb21036e585acf
font_02_sfnt_off00011181.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11181 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1