Malicious PDF — malware analysis report

Static analysis result for SHA-256 016b0b8d35dac89d…

MALICIOUS

PDF

87.3 KB Created: 2021-07-31 12:07:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 472721ea276b8747312983bfb96bba48 SHA-1: 1bf7bd3b6c3722d08525e1b4a1499d8ec442f4e2 SHA-256: 016b0b8d35dac89da76c97f90e68b17e0961be29ab1a0a4c99b37cf8aa53c5f4
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to compromised WordPress sites or disposable domains, indicating a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and numerous external links suggest it's designed to lure users to malicious sites, likely as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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 https://cructi.ru/uplcv?utm_term=present+simple+adverbios+de+frecuencia+pdf PDF link annotation
    • http://al-bandak.com/userfiles/file/ruzapudixezagonogazatumo.pdfIn PDF document text
    • http://farmaciacogliate.it/userfiles/files/15562132444.pdfIn PDF document text
    • http://sotel-perm.ru/site/file/38986928948.pdfIn PDF document text
    • https://globalclassic.org/wp-content/plugins/super-forms/uploads/php/files/56akd36p1ujcir108u19gq48e7/lapirifewafefa.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/50337853811.pdfIn PDF document text
    • http://www.abcklima.hu//data/editorfile/78315511258.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/apdshffhl9rdkkcngqsv8aksj2/miwelomuxisamumopisabobuw.pdfIn PDF document text
    • https://fotofidelity.cz/userfiles/file/16284062285.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d4e93e8a4b7---sakolewivogoxuxiwusoj.pdfIn PDF document text
    • https://baileyelectrical.services/wp-content/plugins/super-forms/uploads/php/files/udd30sgi0i6al75835b6kqj4na/momosokasozetuzifogagefed.pdfIn PDF document text
    • https://trellisdundee.com/wp-content/plugins/super-forms/uploads/php/files/461b3ed4378b5962034dbc5efd60de0a/wugituvogixavefamu.pdfIn PDF document text
    • http://fotografiafrancescosomma.com/userfiles/files/nunelekumirakasakamasapof.pdfIn PDF document text
    • http://netpost.vn/upload/userfiles/files/55286139545.pdfIn PDF document text
    • https://faceless.me/userfiles/files/9121298892.pdfIn PDF document text
    • http://saga.diamonds/uploads/ckfinder/files/47653145982.pdfIn PDF document text
    • https://northwestconvention.cz/data/files/66249828800.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/79mpocdmd2pvjl83ierihlqmh6/72425446199.pdfIn PDF document text
    • http://dambi.pl/userfiles/file/7457996277.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080d09d075b6---62885486089.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd68dc10be4---guvixe.pdfIn PDF document text
    • http://topspeed4wd.com/ckfinder/userfiles/files/wuzizap.pdfIn PDF document text
    • http://jjinline.org/file_upload/file/rabuzip.pdfIn PDF document text
    • 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_off0000ed15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED15 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001052c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1052C 11088 bytes
SHA-256: b0c883f131e438a144e6c53adb5e7fca821eb1bc862577e2b9b74cf9e35b7062
font_02_sfnt_off00011ed4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ED4 18808 bytes
SHA-256: 0044817467fac660bc635194e5f32c8e0068f04e29baea341ecf8a15e833985b