Malicious PDF — malware analysis report

Static analysis result for SHA-256 c57abf1663813278…

MALICIOUS

PDF

82.4 KB Created: 2021-09-04 20:49:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: a483a9d30e6dada521b9e18f50d52784 SHA-1: b774f7e05ba1490b2127f13977874a5ad61ca18b SHA-256: c57abf16638132782d7219e07ec59e329f6e0d6af6711df660e02550b33c662d
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with numerous URLs pointing to compromised CMS upload directories, suggesting it's used for phishing or distributing further malware. The presence of multiple distinct hosts and the use of 'utm_term' parameters in some URLs further support the link farm and potential phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/29a393a44b43739ce3ac3e6cee8d144e/4825367828.pdf In PDF document text
    • http://allycatering.com/userfiles/ponopi.pdfIn PDF document text
    • http://vtvxm.vn/userfiles/file/84394617607.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/5d924870bac72a5f7a8688d68f2d4692/pawolazonixesaxovov.pdfIn PDF document text
    • http://debsluxe.com/clients/1/17/174397649ed9f07baa8f9d9f48c72a4d/File/1008984899.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/9dc8260b8ff9a6c76cfd624604c151f4/gidakesutakaduwitamaso.pdfIn PDF document text
    • https://mancomunidadvaldizarbe.com/userfiles/files/78964748592.pdfIn PDF document text
    • http://xn--franzsischebulldoggen-lec.eu/userfiles/file/sazakogesebezulifu.pdfIn PDF document text
    • http://zonazero.es/userfiles/file/wugemedulide.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c3702931c9---29603582803.pdfIn PDF document text
    • https://samoinstitute.mn/uploads/assets/file/kibikeledo.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/23527168271.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160f6b42a7a11f---10824548083.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2bb4d1df4e---vapefasimonefevak.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/63893gh7r12ns75vj1997cl79o/74564563786.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1607e5d8168f32---69757482482.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd0a15daef3---39186810218.pdfIn PDF document text
    • https://businesslife.com/content/files/87259793675.pdfIn PDF document text
    • http://bobhendrix-law.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/53056284181.pdfIn PDF document text
    • http://aliceinformaticasrl.com/user/pages/kanisibil.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160a1f196e6404---43335745696.pdfIn PDF document text
    • http://phuocthuan.vn/images/pic/file/34092349670.pdfIn PDF document text
    • http://tentimesneedlehill.com/UPFILE/userfiles/files/rekebitanufoladiguku.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd43fd78ded---ligalakuwobobozeta.pdfIn PDF document text
    • http://sirindhorn.net/upload/File/nemuwizolizubawanoloxo.pdfIn PDF document text
    • http://miele-service-center.ru/uploads/files/74387011294.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/7862d5d1ea0b48d2eebbf3add7d2077b/6107561422.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=why+digital+transformations+fail+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://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_off0000de52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE52 17268 bytes
SHA-256: fcc31af0bf9e5c4ecc898ead705114da565224644f8a73059ec293b1f48386bd
font_01_sfnt_off00010a98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A98 10920 bytes
SHA-256: 526458d26ea6f4e00deb64ca004f22664d38549e21fd55d9169b00a00c44d1e9
font_02_sfnt_off00012379.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12379 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1