Malicious PDF — malware analysis report

Static analysis result for SHA-256 1cd4b5d38169a777…

MALICIOUS

PDF

103.6 KB Created: 2021-09-05 13:24:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: d27064276de61c93aaf5af5491a3281f SHA-1: c7cd6b5e9133c11f6e41cc4c15ab516737d8b1ca SHA-256: 1cd4b5d38169a777d315ba1e5f681d28c7b07d043738e3dda711a7e55c2d71b7
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed for SEO manipulation or to distribute further malicious content. The ML classifier strongly indicated maliciousness, and the presence of external URIs and compromised CMS upload links further supports a malicious intent. The file's structure and content do not indicate a specific malware family, but the overall pattern suggests it's part of a phishing or content distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://oniceh.ru/uplcv?utm_term=dermatologia+sampaio+pdf+download PDF link annotation
    • http://www.cbs-emballages.com/upload/file/99643031329.pdfIn PDF document text
    • http://abarappresentanze.it/userfiles/files/siketevifonovutamidi.pdfIn PDF document text
    • http://arunimaflavours.com/userfiles/file/gokomogimubosowavejola.pdfIn PDF document text
    • http://writtenmail.com/upload_images/file/pevakuma.pdfIn PDF document text
    • http://buyyoutubecomments.com/ci/userfiles/files/limonesilogen.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac4183d9cf2---gezugapoxutademurajuxe.pdfIn PDF document text
    • https://www.charroninc.com/wp-content/plugins/super-forms/uploads/php/files/2886c96571631d8642b14ed6dd15a0ab/22199109950.pdfIn PDF document text
    • http://conflictfreeelectronics.com/ourprojects/chowki/UserFiles/renuka/file/wilotu.pdfIn PDF document text
    • http://cukierniabrzezinski.pl/www/artizam/fck/file/datenoxutuwowez.pdfIn PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/aec130ae3c20a9330323269e144f45d4/1411181085.pdfIn PDF document text
    • http://huiking.cn/uploads/file/271347585927.pdfIn PDF document text
    • http://alfavit.tv/userfiles/file/90470867253.pdfIn PDF document text
    • http://rulada.by/upload/editor/files/fulejomasew.pdfIn PDF document text
    • http://atiksigorta.com/files/62436999954.pdfIn PDF document text
    • https://binarbaidfabrication.com/public_html/userfiles/file/57043196368.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609d30ea11948---pibafisixava.pdfIn PDF document text
    • https://torbay.ru/images/uploads/file/wamefixiw.pdfIn PDF document text
    • http://delawaretravelmedicine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d7e1b10a65---bomumatiwovirokutu.pdfIn PDF document text
    • http://tunglamgarden.com/images/fck/file/94103251118.pdfIn PDF document text
    • http://bwc.lt/i/36482044303.pdfIn PDF document text
    • https://fiscalonline.eu/app/webroot/files/userfiles/files/mewoxu.pdfIn PDF document text
    • http://fuyu.010bi.com/ckfinder/userfiles/files/46923354354.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_off0001261c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1261C 10928 bytes
SHA-256: 557c4fd880a08181dbedd3e0c2376cd9ccbb5361ef72b26ba71ef3136c52c18d
font_01_sfnt_off00013f3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F3E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015750.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15750 21036 bytes
SHA-256: c3d318d1d206baba50b5b9defcc302079bb83f4593643b06cce4058d6c66899c