Malicious PDF — malware analysis report

Static analysis result for SHA-256 b13bd22ea8121642…

MALICIOUS

PDF

71.2 KB Created: 2021-09-26 01:09:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 63f09e09abe57595fe870ada8661909b SHA-1: efaef6a1d18681782c8c4bad63a0d222a5716f61 SHA-256: b13bd22ea81216421d4a97da8cb96056752b125e0cf00f28fb4d6a7d869bddc7
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or 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. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the heuristic firings clearly point to a malicious link farm strategy.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://vanphongphampmc.com/upload/files/dodom.pdf In PDF document text
    • http://imoroz.by/upload/file/74528104702.pdfIn PDF document text
    • http://koyomisushi.com/uploads/files/xewuzedafewoxamivuz.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161327c37151b1---lonopuzuworofakazej.pdfIn PDF document text
    • https://renewone.de/files/58699908556.pdfIn PDF document text
    • http://nonstopsushi.com/uploads/files/42605419142.pdfIn PDF document text
    • http://aktifimmo.lu/userfiles/files/65390111661.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614f9927d83a4---25993539273.pdfIn PDF document text
    • http://indcms.testingmachines.com/images/file/mupolatelexazinimawukubok.pdfIn PDF document text
    • https://wemservice.com/ckfinder/userfiles/files/kugebiwaxaleraguwojurowo.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/zitiw.pdfIn PDF document text
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/3a3669d6a96847201659c07a25ea21bc/bekaxok.pdfIn PDF document text
    • http://gesundheit-im-blog.de/userfiles/file/68739364542.pdfIn PDF document text
    • https://2b3la571ga-70p.com/contents/files/dowejapisodekot.pdfIn PDF document text
    • https://excellencetogether.com/img/files/file/27835099425.pdfIn PDF document text
    • https://botroul.be/uploads/14335430565.pdfIn PDF document text
    • https://pottoka.info/files/galeria/files/28940317058.pdfIn PDF document text
    • https://textosolutionslinguistiques.com/upload/editor/file/jawekubejipilo.pdfIn PDF document text
    • http://consade.com/userfiles/file/botaxisiwakafuxezepik.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/5st4frv9rlkmiig6r2390dcbuk/xejijiputovuk.pdfIn PDF document text
    • http://wooshin.kr/uploaded/file/4021210006131bc04dc8c9.pdfIn PDF document text
    • https://nhaccugiare24h.com/uploads/userfiles/file/12717037867.pdfIn PDF document text
    • https://people11people.gr/uploads/File/19441750768.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1614090c8ec2d0---39999019452.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=can+you+listen+to+itunes+music+on+androidPDF 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_off0000b314.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB314 16216 bytes
SHA-256: 4b1848002142648773682999eecdf70ddc58583ccad4e3dcf5b68686fb0488ab
font_01_sfnt_off0000dc1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC1F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f436.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF436 10776 bytes
SHA-256: 43aaed8501ffd56a287ada812c6d13073c057947f54af78503ab1d56055fc086