Malicious PDF — malware analysis report

Static analysis result for SHA-256 71859bb56490a47b…

MALICIOUS

PDF

91.8 KB Created: 2021-08-23 12:08:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 73b00cbe856825cc1810d6ef77b03952 SHA-1: cd31df7c3b0e9db178388d9d3f87614edf5630c9 SHA-256: 71859bb56490a47b9fd3d8e9c793f28da06a08371cb34083905c4cc3e315c704
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of embedded URLs, many of which point to compromised websites or domains that appear to be part of a link farm. The ML classifier strongly indicates maliciousness, and the presence of multiple external URIs suggests an attempt to redirect users to potentially harmful content or phishing sites. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://medvor.ru/uplcv?utm_term=envision+algebra+1+textbook+answers PDF link annotation
    • http://zetrade.cz/userfiles/file/50363807555.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/mixuvavizuvomilusopafozef.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e1d40207272---98511287629.pdfIn PDF document text
    • https://ascend.sut.ac.th/ce/2017/src/plugins/ckfinder/userfiles/files/37836388254.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/ee31efadi63im4usl8oh43l451/22217742890.pdfIn PDF document text
    • http://gyobel.itpublic/file/xumudosimikaf.pdfIn PDF document text
    • http://beerskiboot.com/img/upload/file/dafezelomipuworoveva.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/530117131h2i5ifqdooikc4h2a/rewimujudo.pdfIn PDF document text
    • http://polins.org/public/userfiles/file/11669512272.pdfIn PDF document text
    • https://fratellifurloni.it/file/guvexig.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e1666327a6---soruzopi.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c4b7aadc96e---77754639914.pdfIn PDF document text
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/di4hnejum1uidjakieriht68n5/55512180378.pdfIn PDF document text
    • http://thermcom.cz/userfiles/file/11934833726.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f3e9d9eb48d---nuvoviturafejupotup.pdfIn PDF document text
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/48fea1a44282caca0e9b375f59d29ebf/waxupit.pdfIn PDF document text
    • http://veterani-pushkino.ru/userfiles/files/92604713336.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/160729b4b001c3---jazujuxeterigaw.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd2b6b8aaa3---visenusemefatelipikore.pdfIn PDF document text
    • https://linardi.ru/files/file/noritavafisokimow.pdfIn PDF document text
    • http://zigzagontwerp.nl/sites/default/files/file/89147944161.pdfIn PDF document text
    • https://wyslijpaczki.pl/app/webroot/files/userfiles/file/xenezugawigujosix.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_off0000fec5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEC5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000116d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116D7 18812 bytes
SHA-256: 45337022268cde3957b4a32f78424a5c0bc7106e58a484286e978c2d39faf950
font_02_sfnt_off000147c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x147C6 10804 bytes
SHA-256: 6b82721ca2ee12c2847f005c28bcce32ecd42f038f477a9b36eb78963360f6c2