Malicious PDF — malware analysis report

Static analysis result for SHA-256 9ad153715ca986b1…

MALICIOUS

PDF

80.5 KB Created: 2021-10-06 21:22:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 10e0bfad6ff4787ce66dd3c61a38a3f5 SHA-1: 6454efb75867a0793595ba06059e4226c834e2bc SHA-256: 9ad153715ca986b13f8fa02cf5efbd529462c8f1a279da1c4cb2ab8cc33868cc
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the nature of the embedded URLs suggests a potential for redirecting users to malicious sites or for SEO manipulation, aligning with a spearphishing attachment vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • 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://infrive.ru/uplcv?utm_term=asbestos+lung+cancer+claims PDF link annotation
    • https://phu-komplex.pl/pliki/file/85609259816.pdfIn PDF document text
    • https://dom4m.com/userfiles/files/8320606675.pdfIn PDF document text
    • https://cissud.it/uploads/ck_editor/files/salolamomiwelinofox.pdfIn PDF document text
    • http://galantemontagnana.it/ckfinder/userfiles/files/zipopadekizavava.pdfIn PDF document text
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/161494d05e3656---38627543275.pdfIn PDF document text
    • http://fundacionecla.org/resources/original/file/busologuwesap.pdfIn PDF document text
    • http://laptopplus.be/app/webroot/files/userfiles/files/63398739170.pdfIn PDF document text
    • https://soportedevida.mx/ckfinder/userfiles/files/98451244883.pdfIn PDF document text
    • https://artinterior.bg/userfiles/file/wapuloporamikaborevazesax.pdfIn PDF document text
    • http://rezidencianestor.sk/app/webroot/files/ckeditor/files/faxuvurotekaxuzonofitibe.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/161469f0187650---82638631917.pdfIn PDF document text
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/16262ff3edfadf238939fadca729a37e/dobata.pdfIn PDF document text
    • http://swissies.lt/ckfinder/userfiles/files/vozinasixidaxij.pdfIn PDF document text
    • https://we-plus.tw/ckfinder/userfiles/files/51041091387.pdfIn PDF document text
    • http://smwiarus.pl/ckfinder/userfiles/files/30855064093.pdfIn PDF document text
    • http://ayurveda-shiatsu-nice.com/upload/files/vavuzubal.pdfIn PDF document text
    • http://miskolciharsona.hu/pictures/file/2861515617.pdfIn PDF document text
    • http://mikomisushi.com/uploads/files/33457753056.pdfIn PDF document text
    • http://paulbwatkinslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dasizowewomemo.pdfIn PDF document text
    • https://healthlantern.com/ckeditor/ckfinder/userfiles/files/jukozazexufawipil.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/161432b578f31f---54937326157.pdfIn PDF document text
    • http://balone.net/_upload/file///tabupamuwomosodomuwuwoguk.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_off0000d61e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD61E 10792 bytes
SHA-256: 79e3d671bcb88b5a3803f24f8a2d35d76aabe847f9509a419215fa8f16d61a9a
font_01_sfnt_off0000ef00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF00 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010712.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10712 18152 bytes
SHA-256: 2482e07d494b60e5778af0dfa27a12431c5683f5df2f19a81d7e8848c3b723b8