Malicious PDF — malware analysis report

Static analysis result for SHA-256 51c6a653328da5c9…

MALICIOUS

PDF

86.6 KB Created: 2021-09-02 04:58:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: a59f68c63177944a88eb4dad3547ef7b SHA-1: f7053d1d02ad8dc085b30cd0562de88f072bf4fc SHA-256: 51c6a653328da5c9d886d1bf254e944160e1d8b2d95b155529b69dba61ec44bf
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, indicating an attempt to execute code within the document. It also features a link farm pointing to compromised WordPress upload storage and disposable hosting, suggesting a tactic to distribute further malicious content or manipulate search engine results. The ML classifier strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087a59ed2645---ludenewizurigawizosujexib.pdf In PDF document text
    • http://lexus-custom.com/js/upload/files/33471656459.pdfIn PDF document text
    • http://esistore.de/userfiles/file/83838405387.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608986f5852e0---13867518734.pdfIn PDF document text
    • https://narimasu-chintai.net/jcfiles/file/52053140158.pdfIn PDF document text
    • http://ikhmongol.mn/ckfinder/userfiles/files/31937507103.pdfIn PDF document text
    • http://life-worldwide.org/assets/uploads/files/pijatunafa.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160755046ca468---wanulabovaxutudexuzatog.pdfIn PDF document text
    • http://yourbuilding.ru/userfiles/files/44048806436.pdfIn PDF document text
    • http://konsultacjenaukowe.eu/Upload/file/ralogodezuwutojumusatoli.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0f97c6b8a4fe7643e271a7861896e88d/nomumilolepig.pdfIn PDF document text
    • http://rolmech-strzelno.pl/Upload/file/gifesoxoz.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c6c7fc308e---69045046269.pdfIn PDF document text
    • https://thietbivesinhsonhoa.com/webroot/img/files/74249075855.pdfIn PDF document text
    • https://kolbandibileklik.com/resimler/files/93207482512.pdfIn PDF document text
    • http://sieuthibongda.net/ckfinder/userfiles/files/13830537780.pdfIn PDF document text
    • https://fallsplat.se/file/13849516637.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/9596tmlamiug76lq3ov1934eo7/16777082555.pdfIn PDF document text
    • http://wonderful-foods.net/userfiles/file/27119322889.pdfIn PDF document text
    • https://bibonatura.com/ckfinder/userfiles/files/44990954724.pdfIn PDF document text
    • https://sportsht.com/userfiles/file/4881194780.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=fun+facts+about+todayPDF link annotation
    • 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_off0000e9ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9BA 20024 bytes
SHA-256: 350ea4417891bba2e72945ff583e3b351a40f9bafa4c80aee42bafb2dc310d5d
font_01_sfnt_off00011d2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D2D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013544.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13544 10432 bytes
SHA-256: 6dc082dc8eeab32960da6cf23dce1042edb3439fd8a1ae399c3d2e135d510748