Malicious PDF — malware analysis report

Static analysis result for SHA-256 7ca7fc638aac6dd9…

MALICIOUS

PDF

72.1 KB Created: 2021-09-16 16:44:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: cd5cd53fedfd4a0dfd5ba39402f9904b SHA-1: 94fd56dc225fbc2126ba2fdeced9e8c543ca3ed7 SHA-256: 7ca7fc638aac6dd9c3467bdd8c20527706b403b997396d5079d270649d78d338
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it's designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://synerhu.ru/uplcv?utm_term=apk+auto+signal+refresh PDF link annotation
    • https://www.dooleysnaturalgas.com/ckfinder/userfiles/files/13758788723.pdfIn PDF document text
    • http://colokit.thienlonggroup.com/Images_upload/files/kuzikuxedux.pdfIn PDF document text
    • http://goldsunjsc.com/upload/files/64068894987.pdfIn PDF document text
    • http://quaint-house.com/images/blog/file/17229806811.pdfIn PDF document text
    • http://kleinschadenexperte.de/userfiles/file/35115578546.pdfIn PDF document text
    • http://rainhouse.kr/data/editor/file/1824099316130d6edf13d5.pdfIn PDF document text
    • http://njchemland.com/upload/files/64051846407.pdfIn PDF document text
    • http://media-production.net/admin/ckfinder/userfiles/files/puguwivaxabusufudalo.pdfIn PDF document text
    • https://fullprotec.com/ckfinder/userfiles/files/zevutu.pdfIn PDF document text
    • http://elsekmont.eu/userfiles/file/87599608074.pdfIn PDF document text
    • http://mauchlineware.com/html/chapelstreet/web/userfiles/files/51394613464.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161301bfcdb4db---76834187511.pdfIn PDF document text
    • http://cw-cut.com/uploads/file/47356401945.pdfIn PDF document text
    • https://habibitours.net/ckfinder/userfiles/files/16332189006.pdfIn PDF document text
    • http://mrs-edu.com/sribati/editor/uploadfiles/591278821.pdfIn PDF document text
    • http://faisaltowel.com/survey/userfiles/files/88331454396.pdfIn PDF document text
    • http://bedrucken24.de/userfiles/file/62665077491.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613e62458c992---xotigudumamelazedaj.pdfIn PDF document text
    • http://zubrcup.by/files/files/lopedefikogexeduso.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/laloxirabaliworowabane.pdfIn PDF document text
    • http://luyenthidhcanhsat.com/Images_upload/files/xosiguziwopak.pdfIn PDF document text
    • https://jobtiara.com/files/files/lawudizurewosalomu.pdfIn PDF document text
    • http://sooclose.eu/upload/File/bizubuzokuxonibefuvegu.pdfIn PDF document text
    • http://vikohasanfiber.com/upload/files/tanifamemexi.pdfIn PDF document text
    • http://myagreement.com/UserFiles/file/gorijavumevutebu.pdfIn PDF document text
    • https://sarna-zapiekanki.pl/ckfinder/userfiles/files/96653638580.pdfIn PDF document text
    • https://delaneyllc.com/ckfinder/userfiles/files/27839431714.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_off0000baba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBABA 15288 bytes
SHA-256: cadad69c95a563c0340b55e02e22bb9e56147106183df029d4ec4a94fe91631a
font_01_sfnt_off0000e171.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE171 10812 bytes
SHA-256: ef42c2b7c8e5191dc987eea0fecbb3b5df53f00fa4226779aa0f6b0a03a7ff16
font_02_sfnt_off0000fa6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA6B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1