Malicious PDF — malware analysis report

Static analysis result for SHA-256 1fa26c5c13c0c2fb…

MALICIOUS

PDF

108.4 KB Created: 2021-09-19 23:36:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d6dc1368e107beed4f159d1e77e08106 SHA-1: 20a368401924a6e1a48a3c0f6b81880d2c5bdd15 SHA-256: 1fa26c5c13c0c2fbb5b5cf973e1feaa9c496dd03e676b73ed316f3b97b560c84
96 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by an ML classifier. It contains numerous embedded URLs pointing to various domains, many of which appear to be associated with compromised CMS uploads or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a link farm on disposable hosting, suggesting a tactic to manipulate search engine results or redirect users to malicious sites. No scripts were extracted, and the document body was unreadable, limiting further analysis of specific user lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

Heuristics 5

  • 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://crewmak.ru/uplcv?utm_term=classification+in+machine+learning+pdf PDF link annotation
    • http://englandmatchshirts.com/assets/file/35834442141.pdfIn PDF document text
    • https://lawrenceyezersky.com/userfiles/file/66443088864.pdfIn PDF document text
    • https://macauroommate.com/ckfinder/userfiles/files/farumemagepewusutojuxonik.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/161474809f3438---zopiwelozanob.pdfIn PDF document text
    • https://tsafar.ir/basefile/tsafarir/files/ponidugil.pdfIn PDF document text
    • http://crestviewshopping.abwingsmd.com/uploads/files/finoxazazorasosipawaped.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613378073ce08---belekapemixokew.pdfIn PDF document text
    • http://wagnerpc.com/userfiles/files/gimubolijuvijije.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/38793111217.pdfIn PDF document text
    • https://onthespothousing.com/userfiles/file/kanezu.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147596d4b511---15473394645.pdfIn PDF document text
    • http://asckhn.com/acskhn/userfiles/file/dosakinenafewejimug.pdfIn PDF document text
    • https://cabsfromheathrow.com/userfiles/file/73367326205.pdfIn PDF document text
    • http://soluzionebenessere.eu/userfiles/files/riguman.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f1f61d6d20---22182489474.pdfIn PDF document text
    • http://www.enjoyvaltellina.it/admin/ckfinder/userfiles/files/tosagisuloribifitugawemex.pdfIn PDF document text
    • http://mtcongnghiepxanh.com/upload/fckimagesfile/53169439122.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613d64a036344---tijot.pdfIn PDF document text
    • http://bluebirdcanada.com/FileData/ckfinder/files/20210919_56D86405A483CB6A.pdfIn PDF document text
    • http://adice-area.com/pictures/files/xowugu.pdfIn PDF document text
    • http://gpsputhuppally.com/userfiles/file/kamalomanavevadazar.pdfIn PDF document text
    • http://avvocatoandreabruschi.it/userfiles/files/99199645852.pdfIn PDF document text
    • http://debten.net/UserFiles/File/89279023429.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_off00014317.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14317 18028 bytes
SHA-256: 875a8f235cd586043844572171ffe2db3b6272796293d0cb99c5563188c4e256
font_01_sfnt_off000171ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x171FF 11096 bytes
SHA-256: a79b9ce39a2648f166bebd733fd2d0457182030c875c584e76e7cfd838f07d8f
font_02_sfnt_off00018b74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18B74 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1