Malicious PDF — malware analysis report

Static analysis result for SHA-256 adb7134038c474b4…

MALICIOUS

PDF

73.0 KB Created: 2021-08-27 23:03:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 5ce1b273b83ff6d5c96fe88ce5ac72fc SHA-1: 59e1f83cfbd602a2352d9ce0b569db781a3b44fc SHA-256: adb7134038c474b43375c64db9d6ccfbf252431f2ea0c0bf795241aa98144ad9
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The file functions as a link farm, containing numerous URLs pointing to PDF files hosted on compromised websites. These links are likely used for SEO manipulation or to distribute further malicious content, as suggested by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. No scripts were extracted, but the presence of multiple unknown PDF links suggests a downloader or redirector pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607335cbe4e34---binigumow.pdf In PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b290556937b---ragirodamidinutuv.pdfIn PDF document text
    • http://okfilm.kr/userData/board/file/pudaputavafawaliwido.pdfIn PDF document text
    • https://goldenlinejsc.com/userfiles/file/7445801015.pdfIn PDF document text
    • http://centreforeffectivecoaching.com/media/file/92706359640.pdfIn PDF document text
    • https://cakesandcupcakes.net/userfiles/files/39486962264.pdfIn PDF document text
    • https://alarrabnews.com/images/content/content/file/35523294053.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1611274975fae6---44806652036.pdfIn PDF document text
    • http://amctop.com/board_data/editor_img/file/202106090546.pdfIn PDF document text
    • http://loveperfectionschool.com/upload/file/tupatesefi.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/97abf8cd9568bd270664586c1df6e71f/4434647416.pdfIn PDF document text
    • http://www.chp.pl/ckfinder/userfiles/files/46659411841.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/16080ba3f7e234---46632080525.pdfIn PDF document text
    • http://galettedesrois.hu/userfiles/file/17780191563.pdfIn PDF document text
    • https://rijst.nu/userfiles/file/xazuvoxakitamiz.pdfIn PDF document text
    • http://barbusci.it/maisUserFile/file/1041203867.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/jansu8vdr8b4sfoouhd2a73t42/60506085316.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fcc4bf076b---sikenumaz.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/cacd4b6a61d0891266760a6e89cad1dd/4130810089.pdfIn PDF document text
    • http://wienbildarchiv.com/upload_files/files/37825799061.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/5ccfe1dc454168b6164aef05bd5a27e5/kotadibiwovimexod.pdfIn PDF document text
    • http://perfectthesale.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fac07c9ceb---55336072931.pdfIn PDF document text
    • http://tikatalog.sk/_files/file/13295443389.pdfIn PDF document text
    • https://ariconium.cz/webpagebuilder/ckfinder/userfiles/files/89589643750.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/9313920688d817f06928ac6b16e7dbc2/58814855078.pdfIn PDF document text
    • http://gourmethousemacau.com/UploadFilesfile///66145724095.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=thanksgiving+coloring+page+pdfPDF 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://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_off0000c1db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1DB 16100 bytes
SHA-256: 5f24eb536ce6643c12bc1bcc94d5e7b3009b849e33148d532c61026db6579ae3
font_01_sfnt_off0000ea8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA8E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000102a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102A5 10920 bytes
SHA-256: 7a8fb9c37a6c86a36004bfbb0bd8ba834bbb1b95fe0b1c79e4ea0c6293a08764