Malicious PDF — malware analysis report

Static analysis result for SHA-256 c53b5e9b5369a1a1…

MALICIOUS

PDF

83.2 KB Created: 2021-09-07 01:59:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: e3586300e606369bae96de60645df543 SHA-1: 0d50fa4e3965b8da7a9a802838ee79e85e2ed140 SHA-256: c53b5e9b5369a1a15ccc02ce615ea013bf55f6dfa347693004094ce26f300582
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to numerous external websites, many of which are hosted on compromised CMS uploads or disposable domains. The embedded URLs suggest a phishing or SEO manipulation campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://oniceh.ru/uplcv?utm_term=frp+mechanical+properties+pdf PDF link annotation
    • https://syntellect.ru/Repository/file/1150214886.pdfIn PDF document text
    • http://innotack.com/userfiles/files/72817840750.pdfIn PDF document text
    • https://xn--80aggmy8c6c.net/UserFiles/File/72126217995.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acd4524d747---77762148911.pdfIn PDF document text
    • http://abogadosaguilar.com/ckfinder/userfiles/files/51015266512.pdfIn PDF document text
    • http://xn-----6kcaheblih5ab0a6afqbzoqe.xn--p1ai/ckfinder/userfiles/files/2225730625.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/6c0a2d42b9e4bd53849f33256e19ffa4/rabatuwuvodisefumuxet.pdfIn PDF document text
    • http://hicoweld.com/shop/fck_file/file/suwunegi.pdfIn PDF document text
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e91c4d8a280---sozumonagesizeji.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/16073723f39329---87128019325.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1606f4202345f8---lisakodab.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6bf59327e7---fowojobesano.pdfIn PDF document text
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160bdac82a9ccb---92558507886.pdfIn PDF document text
    • http://school15-tyumen.ru/f/rinivozalux.pdfIn PDF document text
    • https://vadihosting.com/calisma2/files/uploads/24751368146.pdfIn PDF document text
    • https://yocarbroker.com/upload/ckfinder/files/popuposasexogapup.pdfIn PDF document text
    • https://inverpalmas.site/aym_image/files/51504751777.pdfIn PDF document text
    • http://sahrugs.com/userfiles/file/45402306351.pdfIn PDF document text
    • http://vitali-schulz-eiskunstlaufen.de/userfiles/files/83123701027.pdfIn PDF document text
    • https://asiaviews.org/wp-content/plugins/super-forms/uploads/php/files/6uipi1p76so81e4a4mb7098qh1/sakezixa.pdfIn PDF document text
    • http://tunapvietnam.thietbiotoviet.com/Images_upload/files/50657239978.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1611dd811d4245---pumimo.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/suxebufafuvojabofudak.pdfIn PDF document text
    • http://blatt-gruen.ch/files/6793068958.pdfIn PDF document text
    • http://teenmag.cz/userfiles/file/somegufaguvogiv.pdfIn PDF document text
    • https://gitedu.in/ckfinder/userfiles/files/musuvagigifidegopol.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_off0000e11e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE11E 17512 bytes
SHA-256: bf8757a0c167f070af2498ebfff3f68d5a637a3cc3c009af3c38f81f39190e08
font_01_sfnt_off00010e36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E36 10864 bytes
SHA-256: 2ce72634642081051069aa4fed1117de4248e2c52ff2ce600fe97435b44696eb
font_02_sfnt_off0001270e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1270E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1