Malicious PDF — malware analysis report

Static analysis result for SHA-256 b40abeba14c0dfcd…

MALICIOUS

PDF

71.3 KB Created: 2021-09-18 11:32:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 79b50749e094e0b6db64333d16a49203 SHA-1: 75807e2b365020780ac8c050f868619a8daacc9c SHA-256: b40abeba14c0dfcdc0f0ffc2b14e756cc9f4c81a3c4201d7cacd1bae126a0e3e
104 Risk Score

Malware Insights

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm. The ML classifier also flagged this PDF as malicious. The primary function appears to be redirecting users through a series of links, likely to obscure the final destination or to manipulate search engine results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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.
  • 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://goldenlinejsc.com/userfiles/file/81344055375.pdf
    • http://soft-pro.hr/upload/datoteke/xerikolidabez.pdf
    • http://kubak-ubezpieczenia.pl/userfiles/file/44499450636.pdf
    • https://stepweystudy.com/ckfinder/userfiles/files/47949256110.pdf
    • https://ckfinder.pamlskovnik.cz/ckfinder/userfiles/files/40210771604.pdf
    • http://www.nachtruhe.info/up/files/71497341521.pdf
    • https://ienter.bg/files/nigisofuluragobare.pdf
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/45b57ad6a8bc8248a77853c65cc29339/31674752284.pdf
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/a4ab24503cb02e7ad2d994a9a3852f9f/51734054780.pdf
    • http://ibrahimalsada.com/pics/file/kitizilitiruxudepus.pdf
    • http://squash-fitness.cz/userfiles/file/nilerovonoxo.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f87416687a---71652602201.pdf
    • http://ipsgroupjjn.org/userfiles/file/3581311834.pdf
    • https://confidence-ist.mktechsol.com/ckfinder/userfiles/files/5478332164.pdf
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161390a524531e---tusakawu.pdf
    • http://michelschuurmans.nl/images/uploads/file/sutoser.pdf
    • https://directorvincentchow.com/fck_filemanager_upload/file/55628867273.pdf
    • https://mandarinkinesiska.com/userfiles/file/56461065128.pdf
    • https://rowanmkt.com/Uploads/ckfinder/userfiles/files/21916019417.pdf
    • http://china-zub.ru/userfiles/file/43663780654.pdf
    • http://csc025.com/userfiles/file/20210918145357_glcy1d.pdf
    • http://autofactory-jin.com/js/upload/files/92889081774.pdf
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138465431099---68714628864.pdf
    • https://digireg.dk/upload/54611544421.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=download+truck+games+for+android
    • 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_off0000b62b.bin
ddb3a115691837dbf7ffe1eee8232d7e3f1a1294c513a1404cf022335dc0a4f7
pdf-font-stream PDF embedded font (sfnt) at offset 0xB62B 11100 bytes
font_01_sfnt_off0000cfec.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFEC 16792 bytes
font_02_sfnt_off0000e7fe.bin
37d5d66d0fcf9be2d45374148f5f087ddb5e1cec0d78c0260714dffadd93b1d4
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7FE 15532 bytes