Malicious PDF — malware analysis report

Static analysis result for SHA-256 5aac268a88bdbe91…

MALICIOUS

PDF

76.2 KB Created: 2021-09-07 04:26:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 851fe17e5f00701eb8a6ad113e9e7aa7 SHA-1: 3abb65d172bbdef08054057da82024ca3b3c2fb3 SHA-256: 5aac268a88bdbe912d4ee9462acafef71d50d528d28f03134ca4790d87618549
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised WordPress sites and other potentially malicious content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, suggesting an attempt to distribute malicious links or redirect users to phishing sites.

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=mean+value+theorem+integrals+worksheet PDF link annotation
    • https://asiaviews.org/wp-content/plugins/super-forms/uploads/php/files/j7ieu5kofj40uuphrm8rd02l46/lupajoxozu.pdfIn PDF document text
    • https://nepalonetours.com/userfiles/files/rafatusopedumevu.pdfIn PDF document text
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/013fa8c11199a0d32a7c3c30fa2f33b6/10704674036.pdfIn PDF document text
    • http://duonglaohanoi.com/userfiles/file/54515806684.pdfIn PDF document text
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/b6ce4ac1ac47165d8c37586c8602d0bb/24743774756.pdfIn PDF document text
    • http://compsult.net/userfiles/file/74876084855.pdfIn PDF document text
    • http://thetownsendfamily.net/clients/a/ab/ab79602242cca8f930cd52af13df1d51/File/64237889072.pdfIn PDF document text
    • http://hebertfamilyreunion.com/clients/3/32/3272330ca4c68e8b1120eb7f178c7a05/File/29735963567.pdfIn PDF document text
    • http://santeh.md/img/files/16714430810.pdfIn PDF document text
    • http://banhangcongnghe.com/upload/FCK/file/godavozakunanegejujegeb.pdfIn PDF document text
    • http://montpellier-business-plan.fr/mbp/upload/images/images/upload/ckfinder/82841225406.pdfIn PDF document text
    • http://bright-mineral.com/uploadfile/file/2021062415434626.pdfIn PDF document text
    • https://www.elitelawnsolutions.co.uk/wp-content/plugins/super-forms/uploads/php/files/sq026ujc4b7grqf0b98itp3nps/sefuduwekuwaruledobopof.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/160985e9d4c061---reziviw.pdfIn PDF document text
    • https://spaslask.pl/wp-content/plugins/super-forms/uploads/php/files/2j7h7kf67tit04jn7e47dbi35a/vazavudaginuvateg.pdfIn PDF document text
    • https://gionggiacam.com/ckfinder/userfiles/files/26993001566.pdfIn PDF document text
    • http://vcelari.naceradec.cz/includes/ckfinder/userfiles/files/55368695607.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e81066f27ab---22564103434.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9a5c99f584---27758371346.pdfIn PDF document text
    • https://radiosmile.hu/upload/file/78047815341.pdfIn PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/cu791vm8i15j7th0j1nnqho8q2/pofovixaradijadatol.pdfIn PDF document text
    • http://gr-chem.com/upload/files/dagafuneluvuti.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a676feda32f---41752155369.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160b5414fd5206---dijarivuzu.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_off0000c1be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d9d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9D5 10892 bytes
SHA-256: 65dd43d7b1d10304dc65afb6c7c08e3affc6d1181e1926ce5bd3683b8da835ba
font_02_sfnt_off0000f2e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2E2 18272 bytes
SHA-256: 7cd87ff7f03d8175602b9db8ab5cdd78b6c8c9e710d933500a2bce2e622cd43b