Malicious PDF — malware analysis report

Static analysis result for SHA-256 521de44b28c196a8…

MALICIOUS

PDF

101.7 KB Created: 2021-08-10 13:04:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7a08af43c9744752b7e77c2c1b811dc7 SHA-1: 1347d78070b55b9dd3e942fee6aea7ec617a7b84 SHA-256: 521de44b28c196a8fec5010d65b983f544a7de7fa114f7e22e7e90f58d71ca6b
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to other PDF files hosted on compromised websites. The primary purpose appears to be to lure users into downloading further malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9877

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 http://adabaskimerkezi.com/upload/file/mokodofati.pdf In PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/2hsmaf2l4toon07rll94obiqkc/gomuwomitiwukida.pdfIn PDF document text
    • http://www.predia.cz/userfiles/file/21869713839.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/2e57a4fb711594201f3e5ab8990751ac/pimuxurev.pdfIn PDF document text
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/0920fd2c179ede559e81b20062dfc470/duzugiwesogafelagukizibig.pdfIn PDF document text
    • http://acpiindia.com/userfiles/file/89076341619.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609b80ca5b489---3639606570.pdfIn PDF document text
    • https://www.albispanaderia.com/wp-content/plugins/super-forms/uploads/php/files/dca4039c11de4ea2524dea9e8076ad97/24117263015.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076890dda78c---naxofo.pdfIn PDF document text
    • http://okmarin.ru/userfiles/file/56415324470.pdfIn PDF document text
    • https://vnjhanoi.com/upload/files/wadufeponovebaji.pdfIn PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a36c67ad838---rajis.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16080cf580e449---1952612851.pdfIn PDF document text
    • https://spacio.hk/attachment/file/filekiv.pdfIn PDF document text
    • https://cargotavio.ru/files/file/nixir.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/a5f33e1c583067e114ebda00ed5238e5/kipebedabo.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/a9fd8ee794a5f7690747e2ae919c25d3/74813585584.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607844e4a9882---gubudeja.pdfIn PDF document text
    • http://aimic.com/userfiles/file/zumunuxubobutav.pdfIn PDF document text
    • http://moristas.com/userfiles/files/2665803368.pdfIn PDF document text
    • http://pro-elec.ru/ckfinder/userfiles/files/75775126997.pdfIn PDF document text
    • http://montaze.org/democms/userfiles/file/21593903496.pdfIn PDF document text
    • http://championshipsportsrings.com/clients/23492/File/66399693868.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/cc7881d47231b9e254d52943240af20a/42068556029.pdfIn PDF document text
    • https://eandjfamilyhealthcenter.com/wp-content/plugins/super-forms/uploads/php/files/b00fd0b4c8a78316c7aa86e30600401b/buvififokawamukulipuka.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e97d04480a1---zepazeluduvivi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=textbook+of+gynecology+dc+dutta+pdf+free+downloadPDF 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_off00012824.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12824 18324 bytes
SHA-256: 796817302938de01d03afb40271731e342c95ccda7190fa5bd555f042e8e1193
font_01_sfnt_off000156c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x156C7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00016ede.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16EDE 11132 bytes
SHA-256: b2e84790c91df0edbd62aa06444be0f8eff3897a1d27bec2cace6a8c32f3c8da