Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c835b30e84e88fd…

MALICIOUS

PDF

77.3 KB Created: 2021-09-07 04:38:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: db543c38d8f29831df2b9b97bf434444 SHA-1: aaf34b79f218c90da05ccc003c47ae75cd16d9bc SHA-256: 8c835b30e84e88fd8c362ca8929c7a908865728302512e6cb9f416571a7ca33b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised WordPress sites acting as a link farm. This suggests the document is designed to lure users to malicious or phishing content. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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.
  • 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://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d81403cc876---34721889747.pdf In PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/4add6df85edff9413e4c337573e63a19/39326259255.pdfIn PDF document text
    • https://bookatowncar.com/userfiles/file/feminanosor.pdfIn PDF document text
    • http://koreanhotpot.com/uploads/files/vuwufugutumef.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c16b7c07563---59769884245.pdfIn PDF document text
    • https://vinamex.info/uploads/news_file/33651368058.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/b9085f2804d3e3bba57b42c33289cb65/85938266814.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e1be5d14ea1---19199910083.pdfIn PDF document text
    • https://hchoanglong.vn/userfiles/file/sufobuzidejunegage.pdfIn PDF document text
    • https://saintarseny.ca/sites/saintarseny.ca/files/file/vizuwofewir.pdfIn PDF document text
    • http://criollo-cocoa.com/userfiles/file/dejixe.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1608c85d097583---mosawunitogomeja.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607da0d0662e7---pejusezesa.pdfIn PDF document text
    • http://ekachaiguitarist.com/ckfinder/userfiles/files/wagotibosotezesedurenanu.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/161366abc5268e---10809059322.pdfIn PDF document text
    • https://refour.eu/wp-content/plugins/super-forms/uploads/php/files/7acde6aeed429d2d53c0c81e971ce387/87705199003.pdfIn PDF document text
    • http://pitin-akutsu.com/js/upload/files/17479792625.pdfIn PDF document text
    • http://www.melloecastro.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079d8805d2c2---lugijodidanutojurad.pdfIn PDF document text
    • http://ziguratex.com/helpdesk/app/webroot/img/userfiles/files/23472048259.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16111f8dfe614c---sezixubixikimaririmos.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607185f4373a4---69702518665.pdfIn PDF document text
    • http://laxycoffee.com/upload/files/dudefemaziluxodenalava.pdfIn PDF document text
    • http://electrogalicia.com/electrogalicia/recursos/archivos/xuvijebixiwa.pdfIn PDF document text
    • https://drrajanmahtani.com/userfiles/files/58193124384.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/992b5c482ed5367239a7827d7e888b34/44931975123.pdfIn PDF document text
    • https://geniodelweb.com/file/3236786276.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=convert+measuring+units+worksheet+answersPDF 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_off0000cb4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB4D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e364.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE364 10884 bytes
SHA-256: f04d92f0f9402e2c3429d9cac011e262e809eae1d2f9d218356823eba14d3b4d
font_02_sfnt_off0000fc7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC7F 16696 bytes
SHA-256: 0aadac860fdca028590b9d1266886091fb8ee158a9bbf74ead4100ff61bb7472