Malicious PDF — malware analysis report

Static analysis result for SHA-256 e81f040ac0a5b293…

MALICIOUS

PDF

85.4 KB Created: 2021-09-07 14:17:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: b70860f744167d4b7b502e08c60088e2 SHA-1: e011334f02a54852de2983d9bc0abd05102e9d2a SHA-256: e81f040ac0a5b293f159d312bdc82490cc5c1f25232ec893df17c52bb0cfc684
156 Risk Score

Malware Insights

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

The PDF was identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Multiple URLs extracted from the document point to compromised WordPress sites, suggesting an attempt to lure users to malicious content. The presence of external URIs and link farm characteristics strongly indicates a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/mr16di3d252kgpbropltqccpta/51133181440.pdf In PDF document text
    • http://calzaturificiocatia.it/userfiles/files/96724168192.pdfIn PDF document text
    • http://logtech.cz/foto/Image/file/1018187205.pdfIn PDF document text
    • http://www.uniformsolutionsforyou.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d275a0043e---bisipibevav.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160865eaea18f4---wikakefizafijuf.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1608c9b8597cbd---2942152635.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/5dc92c9a027add1e28e3d8718cee1565/fasipixuto.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/4f2703c28f37ed363d1897d0792b0a9c/gosisorojaviwarose.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088889e633a1---lilarugude.pdfIn PDF document text
    • https://qfse.co/images/uploaded_files/ckfinder/files/1628601141_ce0c3601bd.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ca5f0c15216---53104162204.pdfIn PDF document text
    • http://pwmtqatar.net/userfiles/file/xeteruvoxamujeboja.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c8c25531231---29107723415.pdfIn PDF document text
    • https://kurashi-kyoiku.com/cms/dat/upimg/file/varasaligexaper.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609ef3ed3fe9b---80793037603.pdfIn PDF document text
    • http://thecreditcrisis.net/clients/73966/File/62837016144.pdfIn PDF document text
    • http://sushimura1.com/uploads/files/jazimidonegegubanesu.pdfIn PDF document text
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16112c8d9f0acd---8374600849.pdfIn PDF document text
    • http://cctechlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zepikebeviwi.pdfIn PDF document text
    • http://lovelyspa.net/ckfinder/userfiles/files/57706384021.pdfIn PDF document text
    • http://ituor.ir/basefile/chartermeinfo/files/19885042710.pdfIn PDF document text
    • http://ms-beauty.com/ckfinder/userfiles/files/vogasetuvewixusebuwukojoz.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/16086805657945---mukesegot.pdfIn PDF document text
    • http://vanguardhungary.hu/userfiles/file/davesemoxafetuburipo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=bivariate+normal+distribution+pdf+calculatorPDF 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_off0000de77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE77 20860 bytes
SHA-256: 3205c371d712d7cf407f990fc9bd9b4047c651d807da982eec6d48735d241e77
font_01_sfnt_off000115a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115A4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012dbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DBB 11140 bytes
SHA-256: 594aef197a0556cd772a82752f25e5ba3d84ea36b58bafd409572a4e2a500acc