Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7608e2406b52db8…

MALICIOUS

PDF

89.1 KB Created: 2021-07-07 08:58:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: d67c9c469e004d1bf9470b49ba71021c SHA-1: a41fd6d72dc766115a3cf10a5e2ffb9260422d44 SHA-256: b7608e2406b52db861346dcb23239011683c3b80d961dd7546c30d260b941545
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous external URIs and is identified as a link farm, with many links pointing to compromised WordPress upload storage. ClamAV detected this file as Pdf.Phishing.Trojan, and an ML classifier also flagged it as malicious. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure suggests it's designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://medvor.ru/uplcv?utm_term=what+are+the+deadliest+excavation+hazards PDF link annotation
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/h5tvcokgdlf9plgv6408ukkimn/48489216418.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/160a4d73b25190---57159946080.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/jdsgn82fge68dflfph7c3o70kg/godinuxoruse.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/jrgs7cb4ec70c195ag719qdcj4/49504897970.pdfIn PDF document text
    • https://psiakocky-potisk.cz/webpagebuilder/ckfinder/userfiles/files/54088760087.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606e3275af4f4---riniranivarujaf.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/54183669914.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/b7e0794570d547575b6dbaddd3db0f0c/zedirisesebazegomefuwe.pdfIn PDF document text
    • https://www.axelendinggroup.com/wp-content/plugins/super-forms/uploads/php/files/3538781bb5625c2bae97f499e8f47e91/minije.pdfIn PDF document text
    • https://iphonerepairservice.nl/app/webroot/files/userfiles/files/rapukuxi.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/100cb698dd7b8277eb5876a445288761/43794687805.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/82467297267.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/4b423b547ed7ea2ec33a5db09ea23c19/levinelizinejupudisoripe.pdfIn PDF document text
    • https://lemanssrl.it/file/buvegubudedume.pdfIn PDF document text
    • http://thermogroup.ru/uploads/files/dimiwuti.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b8a4e95ae9---pisivaju.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160baad6e006ac---xifugilo.pdfIn PDF document text
    • http://caythuocdangian.net/images/files/17998996349.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160a3c7f009513---9139444595.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b493841a6bd---muvarigugifusijamasiluju.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160955a82c82eb---ripojekodizixusozavewo.pdfIn PDF document text
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/mkfisnaiqtpaspbsqgof5i8in4/70220971085.pdfIn PDF document text
    • http://pune-india.info/userfiles/file/86479432997.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/a3c3718675d3c22b20f8314c8eaf7ed0/99455516957.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_off0000fb5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB5B 16780 bytes
SHA-256: f7be4d6e94c5aeb5c970cab2be1ddde5c4fe4a255078d4d2d0d13bfb8b05da72
font_01_sfnt_off0001267d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1267D 10688 bytes
SHA-256: 4496f8dbbf7bff1ba69103c214cafc1b72783506d1a4d8a090e275ecdaa5e014
font_02_sfnt_off00013f0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F0E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1