Malicious PDF — malware analysis report

Static analysis result for SHA-256 b104943d366d06d2…

MALICIOUS

PDF

81.8 KB Created: 2021-09-11 12:52:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: a7e6645c851c2edd19c81442bf5d2e9f SHA-1: 2afce42f6339828bb8fb0ea3c9085d779eb5f8c5 SHA-256: b104943d366d06d2e2ef4882b2d3053d4a89ae9a13e7c537f0b2155299cb8b24
164 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and multiple links pointing to compromised WordPress sites, indicating an attempt to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The presence of a link farm on compromised upload storage is a common tactic for distributing malicious files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/4qqtnt9s6ajdlu6nmuqrg89p12/32324777101.pdf In PDF document text
    • https://dynasty888.com/image/files/20210904_163439.pdfIn PDF document text
    • https://dazhonghua1688.com/ckfinder/userfiles/files/61744718334.pdfIn PDF document text
    • https://ntc-container.com/upload/files/32349812391.pdfIn PDF document text
    • http://casavacanzesanvito.eu/userfiles/files/99955965148.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137c6522dd93---6919310614.pdfIn PDF document text
    • http://gidromall.ru/img/uploads/file/vubujaj.pdfIn PDF document text
    • https://szelvedojavitasmiskolc.hu/files/files/79627869163.pdfIn PDF document text
    • http://szymonadamczyk.pl/uploads/fck/file/zomagesokukurixufesin.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613826784f7b6---86167414147.pdfIn PDF document text
    • http://northmarking.com/userfiles/files/54849849427.pdfIn PDF document text
    • http://cancunday.com/travela/img/files/nemegoribidokuro.pdfIn PDF document text
    • http://tindangnhadat.vn/upload/files/40798930441.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130c78e55e30---pebalevoxu.pdfIn PDF document text
    • http://resortvillairene.it/userfiles/files/ratiwodowofusu.pdfIn PDF document text
    • http://needychild.org/ckfinder/userfiles/files/14282921468.pdfIn PDF document text
    • http://www.phsdcenter.com/temp/js/ckfinder/userfiles/files/gusivipiburomiwape.pdfIn PDF document text
    • http://saringkarnwood.com/UserFiles/file/50837073978.pdfIn PDF document text
    • http://jfe.hk/userfiles/futosinukiwubamewumanuxen.pdfIn PDF document text
    • http://ebara.com.hk/ckfinder/Zenith/userfiles/files/wexigas.pdfIn PDF document text
    • http://nachhilfeschule.havonix.com/ckfinder/userfiles/files/moxodezukejatuwedepagixi.pdfIn PDF document text
    • http://tycoonmedical.com/userfiles/file/vakoje.pdfIn PDF document text
    • https://mraos.com/web/userfiles/file/96606227429.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=http+custom+mod+unlock+configPDF 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_off0000d8e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8E5 18536 bytes
SHA-256: c5dbaed8a6ddf57e5d9862213314e3d9cb386831539e1a8b9013477081af4312
font_01_sfnt_off00010956.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10956 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001216d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1216D 10752 bytes
SHA-256: b5d5d17d7f27833795ab05791d4f36d796520251ae8e5c2895102afe6e7c9b11