Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4ac88e928a1e3d3…

MALICIOUS

PDF

81.8 KB Created: 2021-09-23 22:35:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: a2510985e746e403f9ec1aa534d42066 SHA-1: 9081970d703bd4c77473bf30921fd4f7460d5b47 SHA-256: b4ac88e928a1e3d30793ce53f6d9040cf09ea6f5d672816c6b64be2f7e670b79
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which point to suspicious PDF files. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to create a link farm, likely to host or redirect to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to download and execute further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://marikakozmetika.hu/editor_up/vomasuzuvonux.pdf In PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145fc04d53e1---rawazorawajatovulidefow.pdfIn PDF document text
    • http://autoservizimensi.it/images/fck/file/58248150935.pdfIn PDF document text
    • http://veterky.ru/ckfinder/userfiles/files/tuxiwugipa.pdfIn PDF document text
    • http://huarui-bio.com/upload/files/raxepifeluteximaxu.pdfIn PDF document text
    • https://5of7edwardstreet.com/assets/media/files/33585785928.pdfIn PDF document text
    • http://perechen-jurnalov.ru/js/ckfinder/userfiles/files/jojusebiverunep.pdfIn PDF document text
    • http://cib.lin1.ca/phpsites/vertical_living/uploads/file/ribivale.pdfIn PDF document text
    • http://ecme.site/2015/vat/upload/files/kepirewelarugefakeguza.pdfIn PDF document text
    • http://serramentisiciliano.it/userfiles/files/37161000361.pdfIn PDF document text
    • https://anandamsanyal.com/userfiles/file/fekikamirus.pdfIn PDF document text
    • https://ltes2.tw-goods.com/UserFiles/files/29772642196.pdfIn PDF document text
    • https://radmangroup-ye.com/rgfiles/file/52915661068.pdfIn PDF document text
    • http://turbotechnik24.de/userfiles/file/gonubusu.pdfIn PDF document text
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16148220c7c517---93703747745.pdfIn PDF document text
    • http://szyoujin.com/UploadFile/file/20210916004645305.pdfIn PDF document text
    • https://ahirealty.in/admin/userfiles/files/gomovuwiwo.pdfIn PDF document text
    • http://saopauloairporttransfers.com/ckfinder/userfiles/files/wumavigoxuxa.pdfIn PDF document text
    • http://www.agot.pl/upload/file/zusexatitukufekavipinu.pdfIn PDF document text
    • http://joyear.com/ckfinder/userfiles/files/21356750955.pdfIn PDF document text
    • http://oipipleszno.pl/userfiles/file/96473669549.pdfIn PDF document text
    • https://kiaavcilar.com/upload/ckfinder/files/89954003858.pdfIn PDF document text
    • http://www.naturhalles.fr/fckeditor/userfiles/file/lizodubavenopimejiwosikiw.pdfIn PDF document text
    • http://showpelec.com/data/file/20210921_114608_739.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=how+do+i+transfer+files+from+internal+storage+to+sd+cardPDF 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_off0000da6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA6C 17392 bytes
SHA-256: 0a0931a8fbca7bfd4ef6356ebc3cf83b1affbcf7fa2621ee387796a0bb87cd06
font_01_sfnt_off000107ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107CE 10896 bytes
SHA-256: 5d944e42167ffacca4b4e04c85e2fcebf76cae929dc9680511555dbcd2036094
font_02_sfnt_off000120cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120CF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1