Malicious PDF — malware analysis report

Static analysis result for SHA-256 cdf8a3fa96a738c5…

MALICIOUS

PDF

86.9 KB Created: 2021-09-19 01:13:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 2ca985bfb3a31e1b6d51bbf822bc9f92 SHA-1: f01c2e496b4a2c51e698832894dc7ec5cd9d8c75 SHA-256: cdf8a3fa96a738c5d9230d6889c66b8bf9f7cfd9c76a00f2b1957a4da600e258
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was identified as malicious by ML classifiers and ClamAV. It contains a large number of embedded URLs, many of which point to disposable hosting or compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The document body is unreadable, but the heuristics indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://krisoc.ru/uplcv?utm_term=android+dyslexia+font PDF link annotation
    • http://dichvugiayphep.net/hinhanh_fckeditor/file/rikerek.pdfIn PDF document text
    • http://crmloccitanecr.com/campannas/file/tugevubilekegunotuloseduf.pdfIn PDF document text
    • http://osmed.cz/app/webroot/files/files/jejisamudopazuvasurunen.pdfIn PDF document text
    • http://sipzip.com/userfiles/file/47847135670.pdfIn PDF document text
    • https://questyme.com/userfiles/file/26470575108.pdfIn PDF document text
    • http://www.s4b.nl/upload/files/zomekesenav.pdfIn PDF document text
    • http://sgyscom.com/upload_fck/file/2021-9-11/20210911030139200408.pdfIn PDF document text
    • https://salwangurugram.com/files/32772058265.pdfIn PDF document text
    • http://www.rpv-drachten.nl/files/file/kagoruxumor.pdfIn PDF document text
    • https://businessincasey.com.au/application/third_party/ckfinder/userfiles/files/30861405954.pdfIn PDF document text
    • http://accapierre.it/userfiles/files/2308267130.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1614224ddced60---zexozizebu.pdfIn PDF document text
    • http://lepetitjaunais.com/userfiles/file/putuxepetikuwexokene.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/161397e2768736---voralajusamani.pdfIn PDF document text
    • http://www.superior-inkjet.com/login/ckfinder/userfiles/files/gewamo.pdfIn PDF document text
    • https://baglab.pl/galeria/file/51030825244.pdfIn PDF document text
    • http://avtokit116.ru/!upload/files/98657507538.pdfIn PDF document text
    • http://keacg.com/upload/files/mitudiboludal.pdfIn PDF document text
    • https://mcq-exambd.bdbabymart.com/app/webroot/ckfinder/userfiles/files/77943660486.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16142d19d5f081---pomerelowobotumaku.pdfIn PDF document text
    • http://55pluscommunityspecialist.com/userfiles/files/27082708248.pdfIn PDF document text
    • http://caytrong.vn/Images_upload/files/vafusutelosusasilasat.pdfIn PDF document text
    • https://kaemsp.org/upload/editor/file/18729970328.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_off0000efd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFD9 10544 bytes
SHA-256: f32479b5dcfdda55b571268c07bb9aa1c3e5006eff957d3cbcc0403aec490ed6
font_01_sfnt_off0001080a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1080A 18004 bytes
SHA-256: b874f167c04b27b83ad76f2d530c0ca4577683c84794086be42a6f348ae51d7a
font_02_sfnt_off0001364a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1364A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1