Malicious PDF — malware analysis report

Static analysis result for SHA-256 caf450a95fcdec0c…

MALICIOUS

PDF

78.8 KB Created: 2021-03-09 08:55:47 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 65c33bf7ebf4193bf500097d26fff656 SHA-1: cf74ec881201abf51a2d5f00bca7048f8e5f1d9f SHA-256: caf450a95fcdec0c4bda4aa2ea0c836f56807dc3616c07d93ce3dbec58d4fa3a
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous embedded links, many pointing to disposable hosting, and one primary malicious URL. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document's content, though heavily obfuscated, appears to be a lure related to college success guides.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://gimoguvi.ru/wix?keyword=a+pocket+guide+to+college+success+2nd+edition+pdf PDF link annotation
    • https://kevigedevuk.weebly.com/uploads/1/3/1/4/131438682/6796697.pdfIn PDF document text
    • https://pulatufulufu.weebly.com/uploads/1/3/4/6/134610330/aef48c5d74.pdfIn PDF document text
    • https://powotatetodo.weebly.com/uploads/1/3/0/7/130738650/ca94875611f99c2.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/180d6442-b004-47c7-9c16-bfba45b79c44/35921531887.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fdfa8c96-fa70-47ac-9e36-bc023d2962b0/wedakuderesazotosu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5bb44e1d-4d60-49c2-80c4-bb4cca0460f1/what_is_the_best_make_of_chest_freezer.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/de4c1e22-511d-4afa-9217-45b22a6b9c54/kobamed.pdfIn PDF document text
    • https://8650d040-a33d-467d-a608-6706f181f11b.filesusr.com/ugd/61b8bf_d8104c53499c436d9ca37585c91ac26f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/90b26884-4182-409d-a052-1a49d33f6cb8/the_best_of_dawson_2021.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/14b9a321-56a6-4f5e-b087-a3117874b79a/71811469071.pdfIn PDF document text
    • https://724418e0-3ace-43c1-abd8-628b4820fc71.filesusr.com/ugd/6df952_916702c009f342aaa5f967a5ff9bb64d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/3b39718e-22af-47ed-8dea-e6c41c66dc49/15562676010.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/77ed16be-52bf-4c8d-b3a6-7385f5754b31/principles_to_actions_toolkit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e386f48e-60e7-4d66-a8bf-21907ea87536/13277497004.pdfIn PDF document text
    • https://1c684d3d-b1aa-4d58-8f8e-408f9cf37fac.filesusr.com/ugd/64d889_acc21d28798c41648f6bf49f3d1f8219.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/c0a740b2-1632-4bd4-8a7f-92fb278a9d04/vokifebajonizedoxajosewu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c0189a5a-f39d-4ba8-b762-85f71cad325b/how_to_adjust_bobbin_tension_kenmore.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/648293d5-8f62-4f53-9110-b44df726fc0e/modo_de_transporte_ferroviario_ventajas_y_desventajas.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fc9c0e98-e682-4e2e-befe-b98329d938e2/english_idioms_and_idiomatic_expressions.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4c1f355a-6426-47ff-bf52-e5454de15cba/11146649635.pdfIn PDF document text
    • https://8ac5c8e1-9174-427d-95c2-90bebb9f105a.filesusr.com/ugd/44b221_9855296039b5420abe1b7af1f7e3ffc0.pdf?index=trueIn PDF document text
    • 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://scripts.sil.org/OFLIn 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_off0000e21f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE21F 5200 bytes
SHA-256: 66ce2c2cf4a0f84051484a3fe38381c7e6b4951d311c32cb2a595e6f75ea0df8
font_01_sfnt_off0000f3fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3FA 10748 bytes
SHA-256: 48ea1d791c8be2e91b6dbd3b57491c384bedce97477afd8912b4ae480620a271
font_02_sfnt_off000118ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118CE 16084 bytes
SHA-256: 29b8095464fa9501f2379a4c43ca3ba1b1df604f87f2abcbe11fa9bdafb8ec10