Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1cb97627af6d2cd…

MALICIOUS

PDF

79.3 KB Created: 2021-09-10 19:07:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 24a959c50e19e4d7b0266e891440d3f9 SHA-1: fb8326a5b55a6a3f350c7e6aa8746fc985a1c7ca SHA-256: a1cb97627af6d2cdbfe49e34085b5bfaff8dfef7439b52e83154d6a842b1d996
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS upload storage and acting as a link farm on disposable hosting. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the presence of numerous URLs suggests an attempt to redirect the user to malicious content, likely for a download or further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://coretry.ru/uplcv?utm_term=worksheet+of+degrees+of+comparison+for+class+5 PDF link annotation
    • http://www.pibmg.com.br/ckfinder/userfiles/files/files/zogisa.pdfIn PDF document text
    • http://cosonhuath.com/hinhanh_fckeditor/file/mafodejoropatube.pdfIn PDF document text
    • https://smsenerji.com/resimler/files/99524508505.pdfIn PDF document text
    • http://grimastone.ru/files/85723765460.pdfIn PDF document text
    • https://taperagi.com/contents/files/derogasikero.pdfIn PDF document text
    • http://frutapac.com/ckfinder/userfiles/files/89451305566.pdfIn PDF document text
    • http://odontoflash.eu/userfiles/files/buromirenimaraziravigikax.pdfIn PDF document text
    • https://apgr.eu/UserFiles/file/rogupogafalegexobokujuxa.pdfIn PDF document text
    • https://privatecambodiatour.com/userfiles/file/65591584005.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613acdb133e6e---22301246605.pdfIn PDF document text
    • http://franceplus.fr/userfiles/file/bidoda.pdfIn PDF document text
    • https://strings97.hu/userfiles/file/5930079590.pdfIn PDF document text
    • http://nokianhakkablue.ru/ckfinder/userfiles/files/39514070226.pdfIn PDF document text
    • https://mandarinusa.com/userfiles/file/1631008329.pdfIn PDF document text
    • https://cortopolis.ar/userfiles/file/74260113075.pdfIn PDF document text
    • https://escolaalfa.com/userfiles/file/45546197948.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/1j2q1qm2g6n64ihnqrrdb1ns76/faluwugonivilokemebe.pdfIn PDF document text
    • https://matricula.netlandschool.cl/files/jigukamowakagupobajan.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161304da24b333---66981732798.pdfIn PDF document text
    • https://nls.vn/upload/files/67093465652.pdfIn PDF document text
    • http://dansungsala.com/uploads/files/15595043677.pdfIn PDF document text
    • https://www.wroclawmodelshow.pl/ckfinder/userfiles/files/71848662591.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/109359fdf86a593003923051039fe29e/jekolejalatasade.pdfIn PDF document text
    • http://opuspoint.com/ckfinder/userfiles/files/fezowivipujivi.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_off0000cde0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDE0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e5f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5F7 11284 bytes
SHA-256: f6bc38933a46b0050e42763a323e89be49cc6c395867af83db34e7529e41ec7d
font_02_sfnt_off00010023.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10023 18292 bytes
SHA-256: f557da6aff678d3e97bb43f1febf593a1ead0044c92da06f4a307c5c72912229