Malicious PDF — malware analysis report

Static analysis result for SHA-256 55a491000af75b3f…

MALICIOUS

PDF

81.0 KB Created: 2021-06-22 13:53:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 16ef7784f00da32c79a8796134685a8a SHA-1: 776f47d49c37f6659b7da1e7583490943bf53523 SHA-256: 55a491000af75b3f36954c5d34c64da44fd5a5f0d4cbce0f4069bc255d296769
96 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by an ML classifier. It contains numerous embedded URLs that point to compromised WordPress sites, suggesting it functions as a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates these links are on disposable hosting and likely used for SEO manipulation or to distribute further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075cd2627589---36372982220.pdf In PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/ec66072ed512344e5e3b209d6cdcb373/3822625117.pdfIn PDF document text
    • https://www.webplease.it/wp-content/plugins/super-forms/uploads/php/files/kp3pjtr6jn1t90jdmc73q40pcq/96573071043.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608b162ce8a56---xokakejokoko.pdfIn PDF document text
    • https://bcbc3399.com/upload/files/gufuk.pdfIn PDF document text
    • http://hondasushi.com/uploads/files/84002847303.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/d1b65c030c0e1c812a4c46a9b21712f0/dinazatibikatubifi.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/bbc8276f2231f1b435d3bd7ebbe90953/berejadedejenasu.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086c554b1bec---29658468483.pdfIn PDF document text
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/bd7d07be530a055a6c9e803d6e1b3baa/natetigifoze.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abad7bc6f46---60363911393.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a076a17001---59471199874.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160883683b6298---tisowumiwodizifa.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4c004465b6---juxirufutiwawukibupuduza.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/masorumo.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160866fc62ee5f---3137783721.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082ec9d967c5---metotipekejivufagatanizos.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=builtwithscience+beginner+shred+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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eef1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEF1 5260 bytes
SHA-256: ad60c6e1f7542fbc1f0a706d9220654a05ae3564e84b0535c377a0c1b331e47e
font_01_sfnt_off000100d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100D2 11272 bytes
SHA-256: 9c3dae96a02366e8e460209d6315bce5d53bc7fc6c457c52f1e72ca728b6b545
font_02_sfnt_off00012703.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12703 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f