Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b95dc55a191a221…

MALICIOUS

PDF

84.9 KB Created: 2021-06-26 21:31:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f6143f87a93ea68d45cf66d777e2d32a SHA-1: 76470cccca7aff1d5c7058da98c403225bff4dc9 SHA-256: 8b95dc55a191a221090999f6ce42b222304128ac6590e01c892530ebd162b62b
96 Risk Score

Malware Insights

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

The PDF file contains a significant number of links, many pointing to PDFs hosted on what appear to be compromised WordPress sites or disposable domains. This suggests a link farm strategy, likely intended to manipulate search engine results or distribute malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the interpretation of a malicious intent behind the link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • 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://nuraski.pl/wsg/userfiles/vegosugakux.pdf
    • http://contelex.it/userfiles/files/budasomitaxiwisekudesob.pdf
    • https://adepotcustom.com/UploadFiles/file/20210428011013131.pdf
    • https://www.apartamentselsllacs.com/wp-content/plugins/super-forms/uploads/php/files/hflpvm1bc7opjhgntrdgejredu/31859743180.pdf
    • http://syuncyoku.jp/upload/file/pazasas.pdf
    • https://floridainvestment.cz/files/file/nukidasujem.pdf
    • https://www.sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607d35db441fd---49926493463.pdf
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/cd59753611dbe443066014c0d1a55851/safenasupilojedem.pdf
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/8f6120657e12e0908263b2efb77249d4/56248409352.pdf
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/048c6e776ed5ec8a62a299ec32078e98/7074985032.pdf
    • http://vswet.ru/f/49320864021.pdf
    • https://anup.bo/images/files/fatel.pdf
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160bc98ec6d299---mowopifinafajasawenizipi.pdf
    • https://eyestech.in/wp-content/plugins/super-forms/uploads/php/files/cvdka937f2v3l3q8lk77391q9o/56727820079.pdf
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160961db64423d---rarasefalapu.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085c75266bd2---19432430348.pdf
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16092edd80489e---9624244652.pdf
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609a66b7d9fdb---nojajaxazuvej.pdf
    • https://mancomunidadvaldizarbe.com/userfiles/files/lisepinafufenaper.pdf
    • http://nhs1980alumni.com/clients/878257/File/59942755181.pdf
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160c6965975aa5---wogapakokag.pdf
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609f521bd6179---difobituz.pdf
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/tmfqnutd08s9in991t367ii6qn/22842285681.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=business+intelligence+reporting+software
    • 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_off0000e816.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE816 16792 bytes
font_01_sfnt_off00010028.bin
d88d7c28a3dca7160b0fc17e5cd025e14629eef5904e97d53d602f85eb544f58
pdf-font-stream PDF embedded font (sfnt) at offset 0x10028 16968 bytes
font_02_sfnt_off00012ca9.bin
f07b30fb36769ea603430df43cff3b71d61fdaa437d31c146e631899adcad63a
pdf-font-stream PDF embedded font (sfnt) at offset 0x12CA9 10896 bytes