Malicious PDF — malware analysis report

Static analysis result for SHA-256 8528a38ae192bf27…

MALICIOUS

PDF

84.1 KB Created: 2021-09-22 12:13:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 27ed6e73b04df1a972cc80c0df9f35e6 SHA-1: db3d812e92475db2c4ab80b5c7b8282d8a530f0e SHA-256: 8528a38ae192bf2730cd6ea9b26f81af0da56a7d247b5cdef6bb5ea424f86968
164 Risk Score

Malware Insights

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

The PDF document contains multiple heuristics indicating it is a link farm pointing to compromised WordPress upload storage and disposable hosting. The presence of a 'download button' lure, combined with numerous external URIs, suggests an attempt to trick users into downloading further malicious content. ClamAV detection further confirms its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://laborke.ru/uplcv?utm_term=vidmate+2020+app+download+free PDF link annotation
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614176fb08d15---99930364159.pdfIn PDF document text
    • http://wdnederland.nl/file/48889233907.pdfIn PDF document text
    • http://csc0535.com/userfiles/file/20210902213102_si3uz9.pdfIn PDF document text
    • http://franceplus.fr/userfiles/file/7813250047.pdfIn PDF document text
    • http://cl-pub.com/files/files/7038472297.pdfIn PDF document text
    • http://taxicityplus.ru/userfiles/file/81071313967.pdfIn PDF document text
    • http://sadiqandsons.com/userfiles/files/41081873846.pdfIn PDF document text
    • https://zoldlaptop.hu/ckfinder/userfiles/files/55572063324.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/16136373cdcffe---ferobilimamu.pdfIn PDF document text
    • https://artgallery.devctn.com/ckfinder/userfiles/files/12269616207.pdfIn PDF document text
    • http://newbusan.net/FileData/ckfinder/files/20210916_A930C23625BC092E.pdfIn PDF document text
    • https://mn-lawfirm.com/box/userfiles/file/jitibisu.pdfIn PDF document text
    • http://burragebrothers.org/demo/jolie/beta/userfiles/files/93596322707.pdfIn PDF document text
    • https://indoshaolinkungfusociety.com/ckfinder/userfiles/files/gewiseduvozegojija.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/1613b81903d396---xuzodu.pdfIn PDF document text
    • http://viswinkelindex.nl/images/uploads/jamakemos.pdfIn PDF document text
    • https://cmoretv.com/userfiles/bixijorojenetosokuz.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145fcd95d0b3---jibajuto.pdfIn PDF document text
    • https://orangerun.re/photo/files/69596389009.pdfIn PDF document text
    • http://ventima.ru/userfiles/file/9160245052.pdfIn PDF document text
    • http://splogservice.ru/content/files/kufumesodek.pdfIn PDF document text
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613aa2c00179b---25330849522.pdfIn PDF document text
    • http://www.blueoak.fr/image/file/keruzak.pdfIn PDF document text
    • http://urbanelect.com/userfiles/file/57089355505.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_off0000e1de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1DE 10788 bytes
SHA-256: f9e45d434ad5b97c6f0d239d5699c32bdbe07651fed9ead02ce4b62518a06a01
font_01_sfnt_off0000fab7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAB7 18640 bytes
SHA-256: f98650cf76f2dc782fe2d6e0ebf0f39f973df6af56bf65bbbf1520751c302fc0
font_02_sfnt_off00012aca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ACA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1