Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c4c50ef8c4ea835…

MALICIOUS

PDF

83.8 KB Created: 2021-09-06 09:59:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: f4617bdafa23d74377e2d325eade0f82 SHA-1: 8117a76ef1b8328d31d82bbbaa0262e5e32a4552 SHA-256: 4c4c50ef8c4ea8355fc137490d7b3ba2298bac58e2de711b4ce40e4f471cdc3d
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. It contains a link farm pointing to compromised CMS upload storage, suggesting an attempt to host malicious content. The ML classifier also strongly indicated maliciousness. While no scripts were directly extracted, the structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160f0740fc2b60---xosetotepiruvazonuzovas.pdf In PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/h490nhobp1rc0g8i5s48h7ig34/wurejiruxeliwijoxubalaser.pdfIn PDF document text
    • http://physocare.com/Images_upload/files/kerimafe.pdfIn PDF document text
    • http://musthighschool.mn/ckfinder/userfiles/files/45005723384.pdfIn PDF document text
    • http://cephedanismani.com/images/pages/file/62459262567.pdfIn PDF document text
    • http://xn--72c7caerxx0d3a9eve.com/UserFiles/File/baximomagopuzodugotutuk.pdfIn PDF document text
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/a15237c35c6f4b204c87ca1a0993d90b/31032658341.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/l71adg9sikb9ab89r2bmp26ccq/30646689802.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/2021821538362453.pdfIn PDF document text
    • https://jxlmedu.com/file/files/20210727_074129.pdfIn PDF document text
    • http://zge-led.com/luodan/images/userfiles/file/revaw.pdfIn PDF document text
    • http://www.aadhar-interior.com/userfiles/file/lugalu.pdfIn PDF document text
    • http://zhouzhuank.com/v15/Upload/file/2021727173268026.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1608af7af7c1fe---90718500419.pdfIn PDF document text
    • https://legacyltg.com/wp-content/plugins/super-forms/uploads/php/files/8c9908db7c422720e84ffe5c06b62d3a/nilipimisuna.pdfIn PDF document text
    • http://cestovni-postylka.eu/userfiles/file/vozetokagekikifazelukewuj.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/8f3771499886b6b9dc494be3fa8c73bc/97548206459.pdfIn PDF document text
    • https://estoniapools.com/contents/files/85368852048.pdfIn PDF document text
    • https://shidoremicrosys.com/media/senurifatuw.pdfIn PDF document text
    • https://gdr.co.il/wp-content/plugins/super-forms/uploads/php/files/f2237be96aa3929caa96ea3ce4a64130/28939831401.pdfIn PDF document text
    • http://phutungvespaco.com/luutru/files/82663470671.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.net/filespath/files/20210827214640.pdfIn PDF document text
    • http://interel-rus.ru/test/sites/default/files/file/lerelitipage.pdfIn PDF document text
    • https://gberwanda.com/gbe/useruploads/blogs/files/ralegobip.pdfIn PDF document text
    • https://thietbidienmanhcuong.com/upload/files/rofazizasazawefupam.pdfIn PDF document text
    • http://kgmda.com/upload/files/ruzele.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=2018+calendar+pdf+kalnirnayPDF link annotation
    • 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_off0000de3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE3C 10840 bytes
SHA-256: dd319471314c8389c9bd713975a5e11424ec586ca8b3d74d601499341e1e8744
font_01_sfnt_off0000f770.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF770 18792 bytes
SHA-256: adae4e3d3bd160729770e6b8f14ac725e68ad923f62d8d2cf424d0d93291c4fc
font_02_sfnt_off00012933.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12933 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1