Malicious PDF — malware analysis report

Static analysis result for SHA-256 18ff8aa937dc4f47…

MALICIOUS

PDF

80.0 KB Created: 2021-09-17 00:55:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 1897948d6982579f449d1d74d9ccee9f SHA-1: d61ee275484e1357b084b21a744f9068e29fb0e4 SHA-256: 18ff8aa937dc4f47e777e4d721f85e5bfde8985ae0be8672d20557a4a78cf897
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed for malicious redirection. ClamAV detected this file as Pdf.Phishing.Trojan, and the ML classifier also flagged it as malicious. The presence of external URIs and link farm heuristics strongly suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • 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.
  • 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://irlanc.ru/uplcv?utm_term=was+ist+android+launcher PDF link annotation
    • https://ww150001.linebot.net/upfile/files/20210902030909.pdfIn PDF document text
    • https://keyseries.us/userfiles/file/xadatolivuwunowizovoke.pdfIn PDF document text
    • http://korytnica.net/data/files/79101723288.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130adb06242c---zexexafeluwuretob.pdfIn PDF document text
    • http://arcenevents.nl/site/upload/files/mofitogigezenojazepaxukit.pdfIn PDF document text
    • https://actorconseil.com/files/file/9232335714.pdfIn PDF document text
    • http://vonschickenfremont.com/uploads/files/xifozudawetelibe.pdfIn PDF document text
    • http://niezapominajkowo.eu/userfiles/file/10887254798.pdfIn PDF document text
    • https://eletmodguru.hu/files/files/7470146499.pdfIn PDF document text
    • https://fsbulletsandbrass.com/userfiles/files/84018859352.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136fcfdc6681---48541403227.pdfIn PDF document text
    • http://wasserburg.pl/userfiles/file/vudaxobas.pdfIn PDF document text
    • https://muacash.com/webroot/img/files/dipemudegifalo.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136959b8d8ff---sokiru.pdfIn PDF document text
    • http://z-sinpro.com/upload/files/5235307485.pdfIn PDF document text
    • http://drivingschool-brno.eu/files/54167282534.pdfIn PDF document text
    • http://skyrybupaslaugos.lt/uploads/files/fapawovomaju.pdfIn PDF document text
    • https://artgallery.devctn.com/ckfinder/userfiles/files/37500791069.pdfIn PDF document text
    • https://ebus.myskoolapp.com/FCKeditor/FCKimgUpload/file/2125534803.pdfIn PDF document text
    • http://deshdunya.com/blogimage/file/14742332656.pdfIn PDF document text
    • https://ms01bet.com/contents/files/tusepuwoz.pdfIn PDF document text
    • http://myphamnanyno.com/luutru/files/15146678449.pdfIn PDF document text
    • http://j-line.ca/fck_upload/file/71216067068.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/5v61v2tucndjkh0kltnabi8089/masafapoxif.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_off0000c637.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC637 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000de4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE4E 10560 bytes
SHA-256: f4936d3339f0ce7861602c868bf9d0ac237234f43babf1fa7cb2f725a11556d7
font_02_sfnt_off0000f65b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF65B 23232 bytes
SHA-256: b895041c5614ede910d40a87bbf43ee9b9b0e2d8de3f67fff84af97f362e5a94