Malicious PDF — malware analysis report

Static analysis result for SHA-256 421f76e6a0f31974…

MALICIOUS

PDF

90.7 KB Created: 2021-07-25 08:51:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3abc4e3185d8a9c9e0144f908fa7d931 SHA-1: 412275cdee072d614dbbc5bf7185797dfafacf4f SHA-256: 421f76e6a0f319749ce56b7713d3ca0e276d96bd8d92c669cb755122385ec4b1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm on disposable hosting, with many links pointing to compromised WordPress upload storage. While no scripts were extracted, the presence of numerous external URLs suggests an attempt to redirect the user to malicious sites for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

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://fanaf.com/article_ressources/file/ripuvusapu.pdf In PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cb53a9d579---93496586261.pdfIn PDF document text
    • https://garnet-medical.com/userfiles/files/87296245140.pdfIn PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/559f57d3fda6ea6b2f6550acd1578989/12674193147.pdfIn PDF document text
    • https://callhfelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d0871963ee---5069311648.pdfIn PDF document text
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073027c2001d---bugigewenisexemowefixo.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a11c32c3f23---ripenolebatutakokesug.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e68f172fb5---negegonitozuwu.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/160943e8e8a3af---jegimef.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/a0e71e89321863627a6c202e3dc89b16/didozos.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/c3n3ib53hmpdmgadp6qq9i354u/51217144336.pdfIn PDF document text
    • http://cobansut.com/userfiles/file/xipasalowuxogez.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a62937e8c6a---69289348720.pdfIn PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/48bb3d63a7e0bcb71a3471c774a356da/25164112707.pdfIn PDF document text
    • http://whsclass1968.com/clients/f/f8/f849445bb2fb8f42e7c863050dc1ba38/File/vimekefigiw.pdfIn PDF document text
    • https://humicdp.com/uploads/2021-07-24/images/files/jejisiferusifiduxeju.pdfIn PDF document text
    • https://xn--p3t29jo1ed4o4xw.tw/upload/files/fifen.pdfIn PDF document text
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607af9777aa5b---67343903781.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/a6a8932feebb5e1027a8e0c60e6e433e/mokinegogejifalurul.pdfIn PDF document text
    • http://jinistudy.com/_UploadFile/Images/file/79298623888.pdfIn PDF document text
    • http://havefuntogether.com/image/upload/File/kajopopajazeribezuk.pdfIn PDF document text
    • https://ildiko-szepsegszalon.hu/userfiles/file/18372765012.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c73f0cddf2---melolojunepit.pdfIn PDF document text
    • https://amd-export.com/site/upload/file/lavevim.pdfIn PDF document text
    • http://patriabrno.cz/userfiles/files/58961787950.pdfIn PDF document text
    • http://cnp-inc.com/ckupload/files/nijawelavelewuwelumiron.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=morphy+richards+slow+cooker+instructionsPDF 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_off0000fbcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBCB 10996 bytes
SHA-256: 5cc54fbe43fa9cd85a1a5bca592e888bdf15fd8b6eb465c3d7fa1abfa4e966f3
font_01_sfnt_off0001155f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1155F 17872 bytes
SHA-256: 51b5284f98bbf48ed7c27aed23e35774f4a0ed9e9b59c754e188091593ea68ab
font_02_sfnt_off00014447.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14447 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1