Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a615bf2c663ce41…

MALICIOUS

PDF

71.8 KB Created: 2021-10-13 09:50:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 845232670b4de9e3babec2e143b8d004 SHA-1: b6b35126ad78170c018b5b2e0e396d8b0ed3653d SHA-256: 3a615bf2c663ce41dfd726fdf729ec42d62d56c474033d59e16872e8e9bd9905
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to distribute malicious content. ClamAV detected this file as Pdf.Phishing.Trojan, and ML classification strongly flagged it as malicious. The presence of multiple external URIs and a link farm heuristic suggests the primary purpose is to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • 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.
  • 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 http://gomsuhoangminh.com/app/webroot/uploads/files/1901809329.pdf In PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613751fc02894---lofoxijifapivegakobavi.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613a040286ca4---fekevapowizami.pdfIn PDF document text
    • https://www.ftha.org/admin/ckfinder/userfiles/files/fulunebolix.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210913234715799.pdfIn PDF document text
    • http://ranahytta.com/ckfinder/userfiles/files/87077924218.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614010a5a0deb---memojereliguxiwesixopizut.pdfIn PDF document text
    • https://www.afoa.org.ar/backend/ckfinder/userfiles/files/21156704504.pdfIn PDF document text
    • http://bagodilovaspark.hu/userfiles/file/94608970584.pdfIn PDF document text
    • http://gurolmumcu.com/userfiles/file/kowagovabunatapet.pdfIn PDF document text
    • https://dzido.pl/userfiles/file/mawogag.pdfIn PDF document text
    • https://10s317.com/uploads/files/202110061223197532.pdfIn PDF document text
    • http://jtipartner.com/ckfinder/userfiles/files/fuvelonodatimepemivux.pdfIn PDF document text
    • http://markasib.ru/ckfinder/userfiles/files/tepumubewezozaluw.pdfIn PDF document text
    • https://segurosjdd.com/wp-content/plugins/super-forms/uploads/php/files/n558l7nuuau1tgjktjf994plm4/difuxiniwamemazovozorat.pdfIn PDF document text
    • https://leganordavigliana.it/uploads/file/28391828677.pdfIn PDF document text
    • http://francescofesta.it/userfiles/files/savijo.pdfIn PDF document text
    • https://mgs-on-track.com/uploads/misc/files/bikanurefajuzibigu.pdfIn PDF document text
    • http://sl-light.ru/design/img/upload/file/50573793447.pdfIn PDF document text
    • https://highfieldhousehotel.net/nbloom/fckuploads/file/16698226126.pdfIn PDF document text
    • https://simorgh.it/uploads/file/zulitebofaxudesidudoz.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/dupozonoguwosonos.pdfIn PDF document text
    • http://www.premiumimport.nl/ckfinder/userfiles/files/borisag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/5bhJmFgkeCE/uplcv?utm_term=evergreen+science+guide+class+10+pdf+free+downloadPDF 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_off0000b5be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5BE 16108 bytes
SHA-256: b6a7c94d5addff94527a26a4385ccb522a412301a13f8e560274b2bfe9d62029
font_01_sfnt_off0000deee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEEE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f705.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF705 11104 bytes
SHA-256: 601cf19fb28705dbdd84239e00dffc985a3882b7e60eba8ada947560914243e2