Malicious PDF — malware analysis report

Static analysis result for SHA-256 6eb851a281154993…

MALICIOUS

PDF

96.4 KB Created: 2021-09-16 07:16:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 4da02a8f4e2a1d224decf5c4f660e20f SHA-1: 793df440a986fd439964466db111b5a7e3bb4eed SHA-256: 6eb851a281154993db4372a904e9f59182fceefac5c6f29eee0aab84669e5be4
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The document body is heavily obfuscated, preventing analysis of its specific content, but the presence of numerous links and the malware detection strongly suggest a malicious intent to redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9888

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 http://caopump.com/admin/userfiles/file/79540647794.pdf In PDF document text
    • https://4cmedica.com/ficheiros_upload/file/8493803072.pdfIn PDF document text
    • http://islenapuntos.com/campannas/file/xabumusojabolozemumejeri.pdfIn PDF document text
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136ab881d2e8---47698856390.pdfIn PDF document text
    • http://www.srijonihealinghome.com/fckimages/file/20708801334.pdfIn PDF document text
    • http://emeat.ru/var/files/58242814428.pdfIn PDF document text
    • https://nurdagihaber.com/resimler/files/93971941217.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/748305b4d6f569d70f055025c000a15a/semaxegijesewut.pdfIn PDF document text
    • http://consorzio-csa.it/userfiles/files/3527412296.pdfIn PDF document text
    • http://manisafar.com/basefile/marcosafarir/files/gelumowewakurorezuwisareb.pdfIn PDF document text
    • https://stormester.no/files/file/12961532287.pdfIn PDF document text
    • http://hacoauto.vn/upload/files/risufapasejosoza.pdfIn PDF document text
    • http://artsar.pl/userfiles/file/dodorovalopi.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613291cb4d806---174502380.pdfIn PDF document text
    • https://allcreaturesinc.com/files/files/29660436763.pdfIn PDF document text
    • http://ipoz.pl/userfiles/file/kedozezogeloban.pdfIn PDF document text
    • https://uzmanwebci.com/calisma2/files/uploads/laregivibeviga.pdfIn PDF document text
    • http://cissi.it/userfiles/files/sumubipidan.pdfIn PDF document text
    • http://evola.it/userfiles/files/pugisoxobufominedudoj.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/eksjpme8ecuc7lv0tp7q6ql5q2/70796811799.pdfIn PDF document text
    • https://jaukiaplinka.lt/ckfinder/userfiles/files/xazobepomegafimewil.pdfIn PDF document text
    • https://groupunsur3.com/contents/files/sakuxesemawebu.pdfIn PDF document text
    • http://dalnoboy.net/data/filestorage/upload/files/83920734887.pdfIn PDF document text
    • http://ayhancevik.com/images_upload/files/mutafanugamavetunozoj.pdfIn PDF document text
    • https://norservis.com/files/files/roxilagirogebitanerasuxa.pdfIn PDF document text
    • http://toyotarent.hk/FileData/ckfinder/files/20210909_443BBBE51387508A.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=playstation+2+rom+setPDF 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_off00011822.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11822 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00013034.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13034 16832 bytes
SHA-256: d817252cafed1a0edf47c6ad361aae6b605f3e91afbb053491a3cb63efa83118
font_02_sfnt_off00015bb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15BB8 10504 bytes
SHA-256: 798c7822b2ba92e4b8e05a03f617353a90069d840427b6c0135a5bc1c6635770