Malicious PDF — malware analysis report

Static analysis result for SHA-256 823554b1dd10f54e…

MALICIOUS

PDF

106.4 KB Created: 2021-08-06 20:10:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 9f6681f92e7868f5cedaf1bd573becb0 SHA-1: 5245592fe18544c24e09fb795df41e637f082c62 SHA-256: 823554b1dd10f54eb541444fb929cad501d3e2921207789435e8504902302e8a
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with multiple URLs pointing to compromised CMS uploads, suggesting an attempt to distribute malicious content. The ML classifier also strongly indicated maliciousness. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific payload or intent beyond the link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1607e52f12f69d---femujobupegose.pdf In PDF document text
    • http://4bx.pl/public/file/dimupujerusunij.pdfIn PDF document text
    • http://bizbecho.com/pa/trainstation/uploads/image/file/2848881608.pdfIn PDF document text
    • http://sweetbasketsbyjackie.com/clients/864293/File/kosipabufubenonozin.pdfIn PDF document text
    • http://diakmelo.hu/ckfinder/userfiles/files/xutopedekipunatudugumuw.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160774158625a6---gukat.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/ad7bccbacd5811f4d645547304082625/80506171962.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160c87725d1b32---3447920473.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c24665d439f---10306254143.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/huqaiv27emmnu2htq1boonuiqd/nofulexagexiwixezeboniris.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/6uou7v1caa4hbl8605kt5qhrf8/53509517236.pdfIn PDF document text
    • https://tlpnw.com/wp-content/plugins/super-forms/uploads/php/files/a9cc650834226d096f4349decd40f1b6/lepeziterobakuvikesun.pdfIn PDF document text
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/febaf5c3a8461292a60942102dcd1305/lusebotulotexopojexuji.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606d5f7c02a53---13568159275.pdfIn PDF document text
    • https://global-brand.net/userfiles/files/fuwodarujuwupipibev.pdfIn PDF document text
    • http://laserinnsbruck.com/static/xilafejavixupigalofojepen.pdfIn PDF document text
    • https://producedepot.us/userfiles/files/tewagip.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610bb7c77728e---90200273306.pdfIn PDF document text
    • https://al-farh-iq.com/upload/userfiles/file/fulotobuponotipuxukunawa.pdfIn PDF document text
    • http://jcbcharpentebois.com/ressource/site-image/files/lirigufajosiso.pdfIn PDF document text
    • https://gulfsupremesa.com/ckfinder/userfiles/files/tukerojomekofavo.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606d07ddda845---juwojegosuj.pdfIn PDF document text
    • https://barrierball.cl/ckfinder/userfiles/files/lejaxafavi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=free+download+background+music+for+video+presentationPDF 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_off000137c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137C2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00014fd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14FD9 11424 bytes
SHA-256: 5d46c6a0c0b5581a6ec7d924f38dc55f2879d708bf5e6d964f953f96b3ec7885
font_02_sfnt_off00016a6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16A6E 18404 bytes
SHA-256: 4ac97a126eace194300bf0450453f9daa5b90c0fa6ada511bdf3ff8d5a49554b