Malicious PDF — malware analysis report

Static analysis result for SHA-256 8bf824b87b9e2e1f…

MALICIOUS

PDF

80.8 KB Created: 2021-09-06 02:28:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 948e567be8b477a7a4e637df9c594d31 SHA-1: 37beb11bfe5e09993bf96d9c04a68ccef573f049 SHA-256: 8bf824b87b9e2e1f18796f794e1b055ce74a3aee0491bdd34df1c9bf5d3f1940
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs that form a link farm, with many pointing to compromised CMS upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the presence of numerous external links suggests an attempt to redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://crewmak.ru/uplcv?utm_term=worksheet+on+articles+for+class+9 PDF link annotation
    • http://chanakyaaerospacedefence.com/userfiles/file/laxodovexopegog.pdfIn PDF document text
    • https://addsfly.com/userfiles/file/37916843301.pdfIn PDF document text
    • http://bukharaatlanta.com/sites/default/files/file/38823369415.pdfIn PDF document text
    • http://gz-theoutfit.com/UploadFiles/FCKeditor/20210810215538.pdfIn PDF document text
    • http://gucaoyun.com/uploads/file/170912273917.pdfIn PDF document text
    • http://scan3dsaigon.com/upload/files/74607844737.pdfIn PDF document text
    • https://la-klamm.org/userfiles/file/babugilifosofenumun.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/m8ucp0eqq8o32djqo2ik7k0fvm/84125916653.pdfIn PDF document text
    • http://asclyziarskyklub.sk/userfiles/file/nusipifejuvuzekaxiwa.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b54a63e2d0a---30916507350.pdfIn PDF document text
    • http://liily.jp/upload/file/20210728094427.pdfIn PDF document text
    • http://pro-group.ru/userfiles/files/vegirupuvulagozo.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/7bcf6f5dcebc62b7c8bb3ce323638574/gumefilona.pdfIn PDF document text
    • https://nocenzura.space/web/img/podborky/files/75375634147.pdfIn PDF document text
    • http://www.emailposte.com/pictures/zevunakawazavoj.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/c18a53b0f9f5fb91fcc40f1da563764f/52142347441.pdfIn PDF document text
    • http://scandirent-new.ru/uploads/assets/file/ludafotasivipezukuwaj.pdfIn PDF document text
    • https://wagaskar.com/media/73848044104.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160ae40d332650---xikomoxidagogugoxivew.pdfIn PDF document text
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/pf6qgd0f8dg5cdog6c85gpq0sc/3802765159.pdfIn PDF document text
    • https://sensesgrouphk.com/louis/STARKGROUP/ckfinder/userfiles/files/80844516938.pdfIn PDF document text
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.net/ckfinder/userfiles/files/57386879512.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d6ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eee1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEE1 10684 bytes
SHA-256: 1a612414762f712fc6011db6adef95d7df8f6b6b9de3d483ea42c6bf6bb52bf2
font_02_sfnt_off00010763.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10763 17756 bytes
SHA-256: f9da5c8744756168ac906063c4330916580d2d3791f09d8d55b062a8cf6c6122