Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0508513679ff8a9…

MALICIOUS

PDF

121.4 KB Created: 2021-07-02 06:34:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 655a7e6603824be26ce12ec2328c8d37 SHA-1: 49a2450b62b7141bff2000a74197d605700c2a90 SHA-256: a0508513679ff8a964d137664c2f91f49a3517e753823c8e78da89c35d0de5f1
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a high number of external links, many of which point to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to download a second-stage payload. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://holocaustresearch.pl/nowy/photo/file/17991742851.pdf
    • http://artistalexanderkanevskywinnerinternationalaward.com/clientMedia/file/nawasalosutejuliviwiten.pdf
    • http://cjatkinson.com/userimages/kaxakapixitajizofexulitaw.pdf
    • http://crisismobile.com/ckfinder/userfiles/files/kovubunidurokidese.pdf
    • http://maristaslardero.es/userfiles/file/kelol.pdf
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160acc9cd2cb4a---48297853602.pdf
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d21095ba578---vebosaru.pdf
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16072d531eb47d---65586176191.pdf
    • http://perfekttorun.pl/pliki/26017794086.pdf
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1608b753913191---21170923249.pdf
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/v6b8nkaeoct7ppthq807c1jsjj/fulakireferizufulex.pdf
    • https://aspaeng.com/files/image/files/penof.pdf
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/e53b1c08312ec61de74dd9314d8b643c/mitukotiletoratunivo.pdf
    • http://bannermaul.com/userData/board/file/ninuzesexojazo.pdf
    • http://kino-cosmic.ru/sadm_files/zimiluwasafosev.pdf
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a32fc3aef3---59190210538.pdf
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/41fv4muiaisam46cehrh8vktvo/34181837538.pdf
    • https://foxtailmag.net/wp-content/plugins/super-forms/uploads/php/files/41dad3b2b0ef45fb331e1b30b2c25b77/sogizugujisiwovusisufenel.pdf
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607391be37757---lepipixox.pdf
    • http://profisystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606effd8c9bd4---20980036763.pdf
    • http://detaycopymatbaa.com/userfiles/file/29389257485.pdf
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16079001e3bbb3---kalubokiris.pdf
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/ppmpp2nk61cvpas8da258cl058/20196531360.pdf
    • http://alliance-ltd.com/userfiles/19538484537.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=steering+system+free+play
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00017780.bin
d86a7326ccba504afd94d4576ef499b40e6d956fb630878ab619a4d60f1efa54
pdf-font-stream PDF embedded font (sfnt) at offset 0x17780 10772 bytes
font_01_sfnt_off00019047.bin
fcbfa6aa2f7c553d192b6a3e80669226789a541aae98fa0487e0677ddd90007a
pdf-font-stream PDF embedded font (sfnt) at offset 0x19047 17756 bytes
font_02_sfnt_off0001bf42.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1BF42 16792 bytes