Malicious PDF — malware analysis report

Static analysis result for SHA-256 9cadfa375ae121d4…

MALICIOUS

PDF

92.6 KB Created: 2021-08-11 14:41:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 665c6102ed1b6fba892a1fdc9e3e7a93 SHA-1: dd0c479b7de665df81404bb3b9716c5a2df5c613 SHA-256: 9cadfa375ae121d439a4259a46ce43350fb666459a0e5e975a63132af3074539
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document that contains numerous embedded links, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and link farm behavior suggest an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 http://thanuyentea.com/ckfinder/userfiles/files/xokupa.pdf
    • http://esistore.be/userfiles/file/kotuk.pdf
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160943434657ca---kifipuzosajovulepe.pdf
    • http://assytekservizi.com/userfiles/files/jojotefibu.pdf
    • http://racecross.com/upload/edito_fckeditor/file/fadoxuwizabiwitewikod.pdf
    • http://xn--2vxr09c6mc.tw/CKEdit/upload/files/30533701998.pdf
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f119e3a5ae---giloke.pdf
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160747a8101560---16917752580.pdf
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/94a8ee6a2b2147fdc7adc896036efe59/lefafelenidozuxit.pdf
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dabd6972613---gakefazexoxetusadananubis.pdf
    • http://aiswaryamatrimonials.com/fck_uploads/file/47359535265.pdf
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/16079ad0536452---wakefedonogowuzavavefad.pdf
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608628bbc87a6---83566513051.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/ikve1mivof48v6ljpbraq6qa83/feraragixazamapivexovoba.pdf
    • http://novussiteyonetimi.com/uploads/file/96518841876.pdf
    • http://vietthanhstone.com/images/news/file/pejudumoxowivit.pdf
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16076521457f25---79475087683.pdf
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a2ea1edd9b5---nosamusutakakokik.pdf
    • http://appletechsolutions.com/userfiles/file/mabasozefobi.pdf
    • http://asiavent.com/UserFiles/file///rikegizivowinexamakerofu.pdf
    • http://coiffurenais.com/userfiles/file/bopimavasezupasumazafo.pdf
    • https://burstallconrad.com/editor_files/file/nuzujonodu.pdf
    • https://cafe-malaysia.com/contents/file/rorumitulunujan.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=is+geometry+dash+free+on+steam
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000104e2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x104E2 16792 bytes
font_01_sfnt_off00011cf9.bin
9e43767bf9baeceba5c40660f19fe71d72da16d4a71656f241ce1aac147ca4b1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11CF9 10728 bytes
font_02_sfnt_off0001353e.bin
630a76007a5f4bc3116f5959b5230359c0c4ae1de7b4f89ad9e204b050b5cd0d
pdf-font-stream PDF embedded font (sfnt) at offset 0x1353E 17708 bytes