Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb5883d2f9f52a79…

MALICIOUS

PDF

76.5 KB Created: 2021-09-11 17:17:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: e82d16cdfeac646828fea2e66137b90d SHA-1: ac117b63851731ddcb770530a8d78223cce3c635 SHA-256: cb5883d2f9f52a79c2b217fad16807c9278114b139e065f42b975a0c4f98b903
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9901

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://dorrstrechy.cz/UserFiles/File/sifasegakutafivaxubuxenib.pdf In PDF document text
    • https://relans-nn.ru/images/docs/file/32884140748.pdfIn PDF document text
    • http://dreamwith.gni.kr/ckupload/files/kekusoz.pdfIn PDF document text
    • http://generale-bureautique.fr/gdb/files/file/74177022421.pdfIn PDF document text
    • https://topupdana.com/contents/files/67987530351.pdfIn PDF document text
    • http://donghotam.com/luutru/files/84501805282.pdfIn PDF document text
    • http://avvocato-callegaro.it/public/file/neripavukenodiw.pdfIn PDF document text
    • http://www.adarshvidhyasankul.org/userfilesfile/rowalikojitugowalelibowef.pdfIn PDF document text
    • https://girl0229960192.com/upload/users/files/numul.pdfIn PDF document text
    • http://picart-personal.pl/fckupload/upload/file/99370092265.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161351207b49b9---rejasavofobuwuwe.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/17d613cdf84eab4a31e3651d4ded053c/jezirerepinikazokisuj.pdfIn PDF document text
    • http://hzbmsj.net/images/upload/File/ruvukuvu.pdfIn PDF document text
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/1933509316133d57575d20.pdfIn PDF document text
    • https://quimicasorocolor.com.ve/ckfinder/userfiles/files/87063092225.pdfIn PDF document text
    • https://kamarkosong.com/contents/files/devajinuxox.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613781bf2d636---xuvofiwemigaxoxativir.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/161329ddf294d7---17064478621.pdfIn PDF document text
    • http://studiopignotti.it/userfiles/files/rerilaxafix.pdfIn PDF document text
    • http://meadescafe.com/userfiles/file/nenetakil.pdfIn PDF document text
    • http://dlshixiang.com.cn/ckfinder/userfiles/files/34806104482.pdfIn PDF document text
    • https://amgaa.org/temp/files/fakoxorukezigo.pdfIn PDF document text
    • http://mamnonkitty.com/webroot/img/posts/files/lixamizuba.pdfIn PDF document text
    • https://rireenfrance.com/images/upload/files/64433234279.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/9j4v507pdqcsaclgc0oksup7oq/1112707166.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613357d9980a0---vejegorepevi.pdfIn PDF document text
    • https://ruh-center.ru/userfiles/file/doburanilipuzulozoze.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=nonton+online+fifty+shades+darkerPDF 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_off0000c441.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC441 18144 bytes
SHA-256: 18827aad88ee037f3864ff20a3c850e94a27d43ca47de9a420d310f67b53b14c
font_01_sfnt_off0000f370.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF370 10632 bytes
SHA-256: a9deda5b10ae7207cddedf6b0b12196d03b89d8bb45ce7b64430c412789402a6
font_02_sfnt_off00010bc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BC0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1