Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4c96275f22273a2…

MALICIOUS

PDF

71.1 KB Created: 2021-09-16 16:28:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: bb361c7aef3c80b42f65252dcfe3677f SHA-1: b91c1b1cb15d96a78e9a30657090897eb38ec8e2 SHA-256: f4c96275f22273a22496f7785425fd4a853ec9512d08252f321cc332c44da2ff
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to lure users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are consistent with a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://canoe.ro/Extras/ckfinder/userfiles/files/larowalaxuxu.pdf In PDF document text
    • http://dayou.tw/uploadpic/files/202109100910507246.pdfIn PDF document text
    • http://vnos.vn/app/webroot/uploads/files/xiresikuvegaleral.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613b678430472---duduforut.pdfIn PDF document text
    • https://dgssu.com/upfolder/e/files/20210904194624.pdfIn PDF document text
    • http://www.deco-interieure.com/userfiles/file/14612682169.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/16132db8ab3fa9---belelu.pdfIn PDF document text
    • http://cuacuonductudong.com/upload/files/mugefodufepozaf.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16133332c7af1b---29284776250.pdfIn PDF document text
    • http://kondicionery-dolgoprudny.ru/upload_picture/file/texetasekapanukoj.pdfIn PDF document text
    • http://gr-chem.com/upload/files/60156721758.pdfIn PDF document text
    • http://kerekagy.hu/UserFiles/file/25778092531.pdfIn PDF document text
    • http://hyswimpool.com/userfiles/guxusemubonikadelaka.pdfIn PDF document text
    • https://freshchannels.com/home/sites/freshchannels/public_html/ckfinder/userfiles/files/42334646376.pdfIn PDF document text
    • http://cancercareresearch.com/userfiles/file/58700093172.pdfIn PDF document text
    • http://a-mega.ua/images/uploads/file/31009488667.pdfIn PDF document text
    • https://weekendtripskolkata.com/userfiles/file/kopanifobat.pdfIn PDF document text
    • https://urology-andrology.com/userfiles/file/medixewakanusisonuzegetas.pdfIn PDF document text
    • http://euro520.net/userfiles/file/1631713572981321753.pdfIn PDF document text
    • http://stomerijindex.nl/images/uploads/rupinerisun.pdfIn PDF document text
    • http://expnavi.com/sites/all/sites/default/files/file/91384345808.pdfIn PDF document text
    • https://sarenpinler.com/calisma2/files/uploads/73399391266.pdfIn PDF document text
    • http://autoklej.pl/app/webroot/media/files/fotikulipepolenu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=super+mario+rom+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_off0000b680.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB680 15844 bytes
SHA-256: 80da25788bce2774515e0ab32d462b77cd47183998d836435ba4ec5dd097ddfe
font_01_sfnt_off0000df1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF1D 10416 bytes
SHA-256: 0f100ab0b31507446ee74515ad43e6d4fec131d9cd9436a46b14e640e3259662
font_02_sfnt_off0000f69d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF69D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1