Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a61b6fd88d1f8e9…

MALICIOUS

PDF

118.1 KB Created: 2021-06-26 02:25:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 800f26aa086a3207ab1e466e418b9dae SHA-1: d32740065f05a5761e6c4a0c18c9ddafa2af6a8a SHA-256: 4a61b6fd88d1f8e9f6d5c9df673c3a685062b3867d0f0de8083770e9dd2549fc
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. No scripts were extracted, but the structure and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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 http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607cf8240bc5c---poxitetemunilezevilan.pdf In PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609edcb61dce8---xenaturutubatubipisuze.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/9668801729.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607aa6739926c---95727396505.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c5ed047f660---gexojulivafusavixome.pdfIn PDF document text
    • http://skrabl.pl/www/rpbd/fck/file/33650309250.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160894f433af1b---71921353277.pdfIn PDF document text
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a375c5264e3---zamerodeniwavopupudifa.pdfIn PDF document text
    • http://kaies.cn/upfiles/file/97812397312.pdfIn PDF document text
    • https://lea-inc.com/wp-content/plugins/super-forms/uploads/php/files/8c1418c95494e36d192ac09c397a3765/49718589437.pdfIn PDF document text
    • https://kovosluzba-praha.cz/res/file/wibowidamuxezilavomusut.pdfIn PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/9174bb94733509a5e3b25344ca76a3a9/geruvudololurufofoxonu.pdfIn PDF document text
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a1a2b7ed661---80703259941.pdfIn PDF document text
    • https://petala.gr/userfiles/file/laruxinidatadipagapivin.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/eurujln514o140pjlg54sdfrs6/pubaneludafuvufixisu.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092938fda0ce---25189391344.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/160be5bcb066db---36122048442.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1609de15d2afc1---kikisozozogitiru.pdfIn PDF document text
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/da6531593896f35de5a6a51fe72912ea/dokedorogapebatovekab.pdfIn PDF document text
    • https://www.straightmyteeth.eu/wp-content/plugins/super-forms/uploads/php/files/e8464741aa1a26ab657d52b72d017a8b/61818362237.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/fhtguqab5qs4lvodnsqjgqunqi/75760249378.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bee76072ce---nonixevalusul.pdfIn PDF document text
    • http://minicabii.com/survey/userfiles/files/wupujanux.pdfIn PDF document text
    • http://allycatering.com/userfiles/61804861093.pdfIn PDF document text
    • http://say-international.eu/userfiles/file/gomekag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=side+view+of+leg+muscles+labeledPDF 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_off00016950.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16950 18460 bytes
SHA-256: cf38b7c83500f4e58ffba9c345f3eb66ea9ce551b93a64e69ec6bffb31395fc1
font_01_sfnt_off000199bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x199BC 10984 bytes
SHA-256: 1d8ce2111ae632f1c02571707a17cd42a8a6d56c9fc68e689a02aea409948b7f
font_02_sfnt_off0001b31e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B31E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1