Malicious PDF — malware analysis report

Static analysis result for SHA-256 51c37b8d9b95be5d…

MALICIOUS

PDF

124.2 KB Created: 2021-06-26 02:52:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 3392ab3c6c6d08f379cf58664b9450d0 SHA-1: b0b5f02d58a96825fce26b644bf4cfa1e9a10c9a SHA-256: 51c37b8d9b95be5d17f0c8a02ec190435b0b984c53ce33bb693ace1de1fc4b9c
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to host and distribute malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9747

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://allytemp.ru/uplcv?utm_term=intro+to+vectors+and+scalars PDF link annotation
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/dfcdcb51ab686ec45857e99b0b9732a9/jazuliruvopenijexorozajam.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/160895054bc7dd---85854249287.pdfIn PDF document text
    • http://cerezolorente.com/files/cerezolorente/_repo/file/38165824417.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/e2e8ea08cb70751ccabed1d4b2d2f9a1/xezazedakavem.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/415jo110cet0r2ai0tpfdd7r86/27116816424.pdfIn PDF document text
    • http://gesundimjob.at/images/content/files/13872179191.pdfIn PDF document text
    • http://northwestpixie-bobs.com/clients/e/e1/e1941a3904c49320334fd90e0ed9e852/File/54648298869.pdfIn PDF document text
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/5fll0srne1r9oh7ivgd4vqncl9/timinumigakizonewe.pdfIn PDF document text
    • http://0vote.com/ckfinder/files/74812681362.pdfIn PDF document text
    • http://www.aadhar-interior.com/userfiles/file/kajojabotaxorasiridumoso.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a04d3947b7---ravetosefawofuwutaxina.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a3a0bd648b4---xomesatuxuwatijojuziwe.pdfIn PDF document text
    • https://baileyelectrical.services/wp-content/plugins/super-forms/uploads/php/files/n4kjmuojaa9q258vkotab1m73c/darutijile.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/nbc2ct4l6piodbosb3c449o5k1/funatejirepoli.pdfIn PDF document text
    • https://www.kasekimi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608212aaa450e---50054992546.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a954bc070fc---vikijugifunaxolapuvu.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/820cc3fc1f24602d1e4fef9a7c7ff58e/55901312448.pdfIn PDF document text
    • http://gezond-trakteren.nl/kasteel-doornenburg-img/bestandenfile/23569910601.pdfIn PDF document text
    • https://www.picmephotoboothhire.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16078cbb657186---sefefikesesekoxoferesixi.pdfIn PDF document text
    • https://atx-stroy.ru/wp-content/plugins/super-forms/uploads/php/files/5ac3283777c2a08748645b83f69a1fee/revobudetidajazi.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160944aa6a30bd---19484245179.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd32f1e5b3---43296048941.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/94821913807.pdfIn PDF document text
    • http://comp-art.ru/userfiles/file/38261084501.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b60fa21fb3---pikiz.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083c8b7efcdc---xojuwiborax.pdfIn 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00016b02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16B02 10288 bytes
SHA-256: e3dc5513b54990aea8bb43679e55b985dca141340859667bef2976d78b6d8c2a
font_01_sfnt_off00018259.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18259 18844 bytes
SHA-256: cba8a6e370bbaf86a40f77e852b00537770b6b5f1163e693972f88a94f5a465f
font_02_sfnt_off0001b50e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B50E 16348 bytes
SHA-256: 51c964afac6754e15219d4ee140c3d6f6482fbd6b6c6456c3c82d222f54df4e6
font_03_sfnt_off0001cafa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1CAFA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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