Malicious PDF — malware analysis report

Static analysis result for SHA-256 e7846b40874ba2d4…

MALICIOUS

PDF

74.2 KB Created: 2021-09-21 21:57:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0d79c1f3b8e3b31d48b65912d90b70a5 SHA-1: c738a2f58abc1612e80f8e561f3656465faac21e SHA-256: e7846b40874ba2d4eb11db1888af67ccc1e3f63ca3e4e5180fdbc66433723d63
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicative of a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded links are sufficient to infer a malicious purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16142860a00e08---19574380440.pdf
    • https://ykitraders.com/UserFiles/file/21021103132.pdf
    • http://sonarkella.com/userfiles/file/buwegemojivep.pdf
    • http://ydchem.cn/filespath/files/20210910232252.pdf
    • http://greenld.com/userfiles/zusowusokusudu.pdf
    • http://cka-shiba.com/ckfinder/userfiles/files/7188510311.pdf
    • http://rotarylaspalmas.org/documentos/file/55613150662.pdf
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613083954e94c---68693619407.pdf
    • http://karlsbach.de/userfiles/files/sanolazoretezidafutuvop.pdf
    • http://sapientgenerator.ru/files/userfiles/files/89193681819.pdf
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/161306142720ef---64746972293.pdf
    • https://kalashad.com/userfiles/file/42368035291.pdf
    • http://mbeautyconcept.com/upload/content_images/file/36817565660.pdf
    • http://bugaboo-buffalo.eu/UserFiles/File/mereduki.pdf
    • http://aal.tw/uploads/htmlupload/files/88186216687.pdf
    • http://zehanbiopharma.com/upload/files/firaj.pdf
    • http://ventexevent.se/uploads/file/puzakuwamenodonipepud.pdf
    • http://www.naraihillgolf.com/admin/userfiles/file/pimusutix.pdf
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/e376d7eb8e2453adb3d5adcf0461d380/kezijesavavizesatozofeteb.pdf
    • http://wannawwannie.pl/userfiles/file/85536620112.pdf
    • http://alarm.pl/userfiles/file/44249861120.pdf
    • http://gapp.fr/medias/files/75142037605.pdf
    • http://phoiinnhiet.com/images/uploads/files/21970007152.pdf
    • http://chongthamnguoc.vn/img/files/xavatafejiso.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=sky+castle+mod+apk
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b7bd.bin
7a449078b82c51006c8c957107b6fe923fbeab4f192516350ec047bfd4574156
pdf-font-stream PDF embedded font (sfnt) at offset 0xB7BD 19452 bytes
font_01_sfnt_off0000ea8f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA8F 16792 bytes
font_02_sfnt_off000102a6.bin
06c5c200361fbd7ae80b5355592bafb17eed2436ca79565fe7d65ce15ca6db22
pdf-font-stream PDF embedded font (sfnt) at offset 0x102A6 10660 bytes