Malicious PDF — malware analysis report

Static analysis result for SHA-256 36aff3cdd4ac1968…

MALICIOUS

PDF

72.8 KB Created: 2021-09-03 13:00:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: b8a465b437335150c9179ec395282aa0 SHA-1: d4dec6636315e242cc0839c2ae119aeca9d98389 SHA-256: 36aff3cdd4ac196850525cf31ffcc986b64dd3fbc7900ce7d87faa4133ceea77
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and links to compromised WordPress sites, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URLs point to a common tactic of using compromised sites to host malicious files or redirect to phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://philabc.ru/uplcv?utm_term=the+blinding+knife+pdf+free+download PDF link annotation
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160726747e383b---8334201627.pdfIn PDF document text
    • https://juhaszautovill.hu/userfiles/file/89923757398.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be105f725fd---lemewutetodamodemur.pdfIn PDF document text
    • http://ctkupavna.ru/upload/file/76489849659.pdfIn PDF document text
    • http://gardenofsound.com/userfiles/files/43744204855.pdfIn PDF document text
    • http://grandp.ru/userfiles/file/19655228158.pdfIn PDF document text
    • http://tamker.hu/userfiles/file/73072892184.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/rh1tb3md41ueiar6ttuuampi9n/xumowadevuve.pdfIn PDF document text
    • http://www.fred-robin.com/ckfinder/userfiles/files/sazupi.pdfIn PDF document text
    • https://artlabjo.com/userfiles/file/92495181126.pdfIn PDF document text
    • https://hostsolutions.ro/app/webroot/files/userfiles/files/pazemi.pdfIn PDF document text
    • https://xn--80aaijz0c.xn--p1ai/ckfinder/userfiles/files/66836114091.pdfIn PDF document text
    • https://concertwristband.com/resimler/files/56595928627.pdfIn PDF document text
    • http://freetourscadiz.com//ckfinder/userfiles/files/xoxogujamoxolu.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c8f2362e6f2---motosele.pdfIn PDF document text
    • http://cherriestattoo.com/ckfinder/userfiles/files/xerakunipusi.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/fujinadi.pdfIn PDF document text
    • http://vstarmp.cn/upload/files/20210728_022630.pdfIn PDF document text
    • https://personnelcle.com/userfiles/file/kafiso.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608002b214c52---mabajujabuvebatu.pdfIn PDF document text
    • http://atreve.eu/ubezpiecz/obrazy/file/fadasulozimazelogijokeb.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_off0000b781.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB781 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF98 10792 bytes
SHA-256: 93b28abd31604378a42cd3e3112ccb744c3eeb5effb2f6531fd5b311e19c7102
font_02_sfnt_off0000e7ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7EE 17096 bytes
SHA-256: 42a9cb28ed971a6eafabcddf6c8e62e17f0bd19bb8138ad3c2b07238b62a3b36