Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef7a78ae9b9c8ae0…

MALICIOUS

PDF

83.5 KB Created: 2021-09-02 22:10:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 104f8cc2bc81b38936a7fd6f705debd5 SHA-1: d116e4830b00324afd92aafbbfdd353a1bb2efe4 SHA-256: ef7a78ae9b9c8ae0c4012be69d339e905a45af48599913ad89d20636805fae1a
196 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external PDFs hosted on compromised WordPress sites and other disposable domains, suggesting it is used to redirect users to download further malware. The presence of multiple PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1612da07c88505---fefewovulozuzejapet.pdf
    • https://minhvuongthuphap.com/upload/ck/files/xuzepufimelujalasired.pdf
    • http://ahxxzx.com/userfiles/202104/file/1242687471.pdf
    • http://ever-pioneer.com/upload/files/30697319904.pdf
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160708d0a2f3eb---jawerewitosenipevine.pdf
    • http://aczelzalog.hu/tmp/59966443596.pdf
    • http://malopolskiszlakwinny.pl/upload/File/lugesikedugifodovor.pdf
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee4f7a6d25---61848931781.pdf
    • http://saluteebenesseresas.it/userfiles/files/rubokowateburokidirosur.pdf
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b42da378ae7---1237813423.pdf
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ca51c8dc21---62945971154.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/birbdusjiedkmdt3kevgc46v61/dabevimivexod.pdf
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b2a49a95b36---pilububuwizifabatowarokiv.pdf
    • http://omonetach.pl/foto/ilustracje/file/29750290203.pdf
    • http://thefarmatarapahoecounty.com/userimages/57151276686.pdf
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160849b92bc018---risuzipedijabovixu.pdf
    • https://maugli24.ru/wp-content/plugins/super-forms/uploads/php/files/76540d23974b282cc43c66787fc0bc73/disegewaperojitalimuzizo.pdf
    • http://ambulatorioveterinarioilghirlandaio.it/userfiles/files/wojawelojozibikavasu.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a3aba574406---gesusuremusoseweliw.pdf
    • https://pharmawell.eu/ckfinder/userfiles/files/42580925646.pdf
    • https://evg-prague.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a5d756479f1---21662750852.pdf
    • https://banktapeunadana.com/tapeunadana/bank2/admin/userfiles/file/70090422438.pdf
    • https://dbmotorbrokers.com/userfiles/file/88777643142.pdf
    • http://kedehg.com/ckfinder/userfiles/files/weburuj.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=vocabulary+worksheets+for+intermediate+esl
    • 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_off0000ddaf.bin
9480da9b90503ce9d9c3ff0c73e00edd5f5ec7c9b1d87ddce5c99029ddc28685
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDAF 11244 bytes
font_01_sfnt_off0000f7ec.bin
cbcc87bcb24ee4711121ad010bcb63d8e28791f95ab76375ea8b265e970898b9
pdf-font-stream PDF embedded font (sfnt) at offset 0xF7EC 18308 bytes
font_02_sfnt_off000127fe.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x127FE 16792 bytes