Malicious PDF — malware analysis report

Static analysis result for SHA-256 c26605674bb1f773…

MALICIOUS

PDF

80.4 KB Created: 2021-09-10 19:07:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d10d8a6481f3631709ddf76fdab7d11d SHA-1: 64e8bec31f6670ebd4178b40cd24d57b8c395acb SHA-256: c26605674bb1f7730266e1aea312d8b58ae37e80e2ca46412c59f114a5cf5c6e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. Heuristics indicate it functions as a link farm, directing users to compromised websites hosted on disposable domains. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16136efc83a0b2---6356201615.pdf In PDF document text
    • http://aircond.md/upload_fck/file/7154849854.pdfIn PDF document text
    • https://longhoang.vn/upload/files/67218556551.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16136c7dd1a240---tipafotedajirodowomubat.pdfIn PDF document text
    • https://soosekszer.hu/upload/files/40275139220.pdfIn PDF document text
    • https://relaxbotanika.cz/ckfinder/userfiles/files/pusibokunedoxexodonu.pdfIn PDF document text
    • https://glearningsolutions.com/userfiles/files/6410592929.pdfIn PDF document text
    • http://studioagronomoserragiotto.eu/userfiles/files/57251189307.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/33bf9ad034bd571d003ba06998c32fb2/98636653268.pdfIn PDF document text
    • http://eros-arena-reutlingen.de/eros/userfiles/file/nagafa.pdfIn PDF document text
    • http://qcfloor.com/userfiles/file/sixotizafinukixakifes.pdfIn PDF document text
    • http://www.hro.ait.ac.th/js/ckfinder/userfiles/files/vusewuzame.pdfIn PDF document text
    • http://texmet.pl/userimages/file/dojevanuwijojukir.pdfIn PDF document text
    • http://wuyioutdoor.com/userfiles/file/71052563013.pdfIn PDF document text
    • https://orcasproje.com/userfiles/file/88213149047.pdfIn PDF document text
    • http://mindatpeace.us/uploads/files/46432849672.pdfIn PDF document text
    • https://assignmentmart.com/ckfinder/userfiles/files/4292864782.pdfIn PDF document text
    • http://3wsystems.com/shipinc/userfiles/files/9672013505.pdfIn PDF document text
    • https://sharjahcements.com/images/bulk_images/files/kenuwesaj.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/73937643099.pdfIn PDF document text
    • http://k-ookuma.com/js/upload/files/teluzizurifalizepav.pdfIn PDF document text
    • http://socukorglutamatmentesfuszer.hu/ckfinder/userfiles/files/lemaxavubivasu.pdfIn PDF document text
    • http://etoprosto.ru/ckfinder/userfiles/files/18097282616.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=waterfall+chart+excel+2020PDF 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_off0000d71e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD71E 17764 bytes
SHA-256: 6a5b8c090a9797ce1801a7c466c380f3b50570a4cd8c1ab7e265716b2e25d089
font_01_sfnt_off000104ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104EF 10288 bytes
SHA-256: cfb4ee3847bebb89d95d611f71bf292d175c4336529b6c8b5f58f6967416c6fb
font_02_sfnt_off00011c63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C63 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1