Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b52db0ecd101821…

MALICIOUS

PDF

83.8 KB Created: 2021-06-30 04:50:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: ae59ee7f5d636e529a5b20356e670ca5 SHA-1: 4461588a7f0965498cab41196d75b608f9015799 SHA-256: 4b52db0ecd1018217617ac47704b6704059e60a01cdc9402a3c0c21d80145370
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites, likely intended to lure users to phishing pages or download further malware. The presence of multiple distinct hosts and the use of UTM parameters suggest a coordinated effort to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://laborke.ru/uplcv?utm_term=java+substring+from+the+end PDF link annotation
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/f9e0e5a67b0b34e2f2ee7a34a609af40/24377741503.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a673962f72d---mebupunawafagovod.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1607e26a9c5475---86923921988.pdfIn PDF document text
    • https://thejinglelab.com/wp-content/plugins/super-forms/uploads/php/files/2u54oln0jp90cn1vb0apm02h0q/49201048044.pdfIn PDF document text
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d6693b89e8---25170361909.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a272d758259---soxatenilexakomejokibo.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160787f3787505---tamegepu.pdfIn PDF document text
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/aa86316a43e6adfdc08c7a4a47b4fb40/xezupotelel.pdfIn PDF document text
    • https://roweryelectra.eu/app/webroot/uploads/file/16199757899824.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/1n4brk9h4oalsgu7glbk7bu5u5/wugikitudomija.pdfIn PDF document text
    • http://solamsys.com/userData/board/file/xudisarofewawigezab.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076942a09b33---tusemuxejifaduwel.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16099dc3f26bbe---27053616855.pdfIn PDF document text
    • http://animationcoach.com/userfiles/file/sumuregob.pdfIn PDF document text
    • http://bradleyhillsapartments.com/demo/uploads/contents/file/suwazimonaxapiwape.pdfIn PDF document text
    • http://c-amc.com/upload/files/22472838292.pdfIn PDF document text
    • http://clinicaveterinariamontecchia.com/userfiles/files/67618611883.pdfIn PDF document text
    • http://staging.impactredevelopment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b5cef34f49---63486777890.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16098d6c9d10e5---xiridepumotu.pdfIn PDF document text
    • https://imagebeaute.fr/userfiles/file/tirufixesebodesapomugalu.pdfIn PDF document text
    • http://iccj.jp/images/uploads/fckeditor/file/83783661097.pdfIn PDF document text
    • http://firewheels.pe/userfiles/file/29015305012.pdfIn PDF document text
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/f171c51e41fc7ab23ab57031aa2a094b/74432503232.pdfIn PDF document text
    • http://strandedtattoo.net/file/kilonumosedetekojedafeno.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_off0000e364.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE364 11052 bytes
SHA-256: 6ad47917b71a649963335adc6dd0bb2db3f7fdf87e0b9349d12a338de9e63c50
font_01_sfnt_off0000fcc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCC6 17136 bytes
SHA-256: 92a223f9bad150d8845d2067410b3deed68ef8ec2ea583d5c073cd477e606abc
font_02_sfnt_off000129f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129F2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1