Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e643e330bd02672…

MALICIOUS

PDF

84.1 KB Created: 2021-08-26 10:48:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 8bc48d6661a46474b65e7c4a6840afb4 SHA-1: a2a39337e7d52a3893fa4aabe020d33124b32581 SHA-256: 4e643e330bd0267292f8199e2525f3ae0a45f60ef691fdfd0f0c02a51b1963c5
156 Risk Score

Malware Insights

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

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 embedded URLs pointing to compromised websites and disposable hosting, which are likely used to distribute further malicious content or conduct phishing attacks. The presence of multiple PDF files hosted on these compromised sites suggests a coordinated effort to lure victims.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://ddaengshop.com/ckupload/files/50001915555.pdf In PDF document text
    • http://dungcumaymoc.com/Images_upload/files/35035438957.pdfIn PDF document text
    • http://zhfangyuan.com/uploadfiles/files/97347156704.pdfIn PDF document text
    • http://aiken7050.com/clients/5/51/510ae66c864a6d23552e02d1b5190e2c/File/fufidukafed.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb8a379dcbb---jaletapab.pdfIn PDF document text
    • http://scottleddy.net/clients/862555/File/nefosazazuj.pdfIn PDF document text
    • https://xn--fct8ml6mwue.tw/uploads/files/xabep.pdfIn PDF document text
    • https://chmelo.hu/sites/default/files/file/netutaxumejajozunab.pdfIn PDF document text
    • https://www.barrau-philippe-sedeco.fr/ckfinder/userfiles/files/84210362284.pdfIn PDF document text
    • http://cdwy028.com/uploadfile/file/20210605132424.pdfIn PDF document text
    • http://hsi-international.com/ckfinder/userfiles/files/neguzumawokegadebokasap.pdfIn PDF document text
    • http://sanitaerprofi.ch/fckeditor/editor/images/file/rejosodafogenewe.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/e7c0d6e410b1163d9f93b350c9f90c57/fonetinurokoradejupatobe.pdfIn PDF document text
    • https://ehlibeytalimleri.com/resimler/files/55336310713.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c94d74920b3---42274732846.pdfIn PDF document text
    • https://southernlightingsource.com/wp-content/plugins/super-forms/uploads/php/files/090e8778004f22ef421572647df21585/zigarapaxujawuzazidada.pdfIn PDF document text
    • https://shindah.com/images/ckeditor_img/files/remeguzilisowix.pdfIn PDF document text
    • http://weddingceremoniesbybev.com/clients/72651/File/fabonem.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a118882afdc---54044809500.pdfIn PDF document text
    • https://knurussian.kr/DATA/upload/files/202107271124442864.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160711ba41d6cf---kudet.pdfIn PDF document text
    • https://xosobacninh.vn/webroot/img/files/lajuwamad.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=what+does+ep+meanPDF 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_off0000e565.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE565 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fd7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD7C 10412 bytes
SHA-256: b4095341dade0f5a408efac6e15896574442a54a0d432cf5570768bc8b6c7b0e
font_02_sfnt_off000114e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114E6 17472 bytes
SHA-256: 0f5282faf86c47bfcc38872d657df80663e81a82a0b7492ff458d35e9d3d12b1