Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a4f820a531fb342…

MALICIOUS

PDF

77.6 KB Created: 2021-09-06 00:02:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-02
MD5: 98874c08264c99d497ad856dd3a4e3a6 SHA-1: 29b818a636e8fb272ea6656cfe93a540d37c3da9 SHA-256: 4a4f820a531fb3421e6cdd018fdec9ee843aed311ba84cd800646dec0f32008a
172 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories, presents a deceptive download button and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 8

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://reversetheclocknow.com/ckfinder/userfiles/files/77632829436.pdf In PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/gq9h5i6gku6f9tgkg136brvk97/moxefebamix.pdfIn PDF document text
    • http://dachastyle.com/userfiles/file/suzobipavegejaga.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160895bd465b44---12257284857.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160a15784e9040---malaxivezemadeloferede.pdfIn PDF document text
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/53o9psqf0vv3557d0rj0jtaglq/33534457460.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072ef8cc6695---wuxudidumupu.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071ac3bdd539---73226667642.pdfIn PDF document text
    • https://textolinguisticsolutions.com/upload/editor/file/72615661217.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160f848131bd40---48779459944.pdfIn PDF document text
    • https://bompentax.com/quangbasanpham/app/webroot/upload/image/files/86070291994.pdfIn PDF document text
    • https://delaneyllc.cfonewsletter.com/ckfinder/userfiles/files/rumuzofimiwusupujej.pdfIn PDF document text
    • https://www.theoakshealthcare.com/my_content/js/ckfinder/userfiles/files/10656170592.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/062526ad78c8df33328a9b76a471f7de/25472001260.pdfIn PDF document text
    • http://abpaluso.com/upload/file/wikubamesimibafiralexuf.pdfIn PDF document text
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16074399d12243---78544334921.pdfIn PDF document text
    • http://ceramicaartisticamarsalese.it/userfiles/files/fotibabi.pdfIn PDF document text
    • http://santeh.md/img/files/82335278556.pdfIn PDF document text
    • http://a-swiss.com/upload/userfiles/file/5210414170.pdfIn PDF document text
    • https://ptogel1.com/contents/files/potizosokekoletumab.pdfIn PDF document text
    • http://rosniyom.com/userfiles/files/jobasewazumamupirik.pdfIn PDF document text
    • http://capitaloffice.pl/fotki/file/tezamow.pdfIn PDF document text
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/a5006e422db4c497a4e7ac1ed35cb73d/16006439817.pdfIn PDF document text
    • https://houstoncoinshow.org/FCKeditor/file/16166294010.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/65840058452.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=conic+sections+class+11+ncert+solutions+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_off0000c857.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC857 10796 bytes
SHA-256: bb1548c35adfaf8c28d802e1276080d786422bd0213ad18f6cfb00bbbe436cae
font_01_sfnt_off0000e170.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE170 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f982.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF982 18364 bytes
SHA-256: d4c416c53dfdf13f2449900f94f2f02576f74fa962e66bfc629b217eece6def5