Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6ffc9a8dcf3e110…

MALICIOUS

PDF

73.3 KB Created: 2021-09-19 03:05:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: c4da5785efb5910906d822bcb6fd2f88 SHA-1: 454d412a3c0895cb33b53b0327b09ae161f96cac SHA-256: a6ffc9a8dcf3e110b47633e9777b004cd36c740479ba45e2188aeb73d811e6d9
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised websites, as indicated by the 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristics. The ML classifier and ClamAV also flagged this PDF as malicious, suggesting it is part of a phishing or malware distribution scheme. No scripts were extracted, and the document body was unreadable, but the presence of numerous links to potentially compromised domains strongly suggests a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://firesystem.ro/imagini_ws/83411783713.pdf In PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/a1hqq9jg1luj0o745dqoutkrg0/gizokamowewavi.pdfIn PDF document text
    • https://beyondpins.com/calisma2/files/uploads/rejenewobejilu.pdfIn PDF document text
    • http://antasboru.com/guvennet/resimlerfiles/jovabeniduxadumorejubiran.pdfIn PDF document text
    • http://turinhotelcompany.com/userfiles/files/riromita.pdfIn PDF document text
    • https://irish-setter-zucht.info/ckfinder/userfiles/files/4429376310.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132f27712353---gijalifake.pdfIn PDF document text
    • https://store-connector.com/_upload_bilder/_filemanager/file/25380248660.pdfIn PDF document text
    • http://korsorlampang.net/user_img/files/42943668052.pdfIn PDF document text
    • https://estudiowebcolombia.com/ckfinder/userfiles/files/46691141516.pdfIn PDF document text
    • https://pqclass.kr/imgs/file/34155237670.pdfIn PDF document text
    • http://harekatmemuru.com/images/Media/files/1000075988.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/8030183779.pdfIn PDF document text
    • https://safetyhanoi.com/userfiles/file/jabagigaxafowu.pdfIn PDF document text
    • http://lecieldesandes.fr/ckfinder/userfiles/files/81274826373.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/e7b64e302522095268aa795130667589/tijizigikomifejuj.pdfIn PDF document text
    • http://sp3siemianowice.pl/userFiles/files/sekolizonofob.pdfIn PDF document text
    • http://launensia.cz/ckfinder/userfiles/files/fawelisixojufovobelat.pdfIn PDF document text
    • https://vresponse.net/userfiles/file/wixomunibofog.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/161466850a2c00---95540141854.pdfIn PDF document text
    • https://suacuasathcm.com/uploads/files/3685332041.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1613eaea7590ea---76520258802.pdfIn PDF document text
    • http://bloemenwinkelindex.nl/images/uploads/gudosowi.pdfIn PDF document text
    • http://graficaeformazione.it/userfiles/file/10198214085.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=live+football+websites+freePDF link annotation
    • https://b2cdemo.tickets.com/content/files/54997325745.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_off0000bcb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCB0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d4c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4C7 10352 bytes
SHA-256: c64c75c83c085f3b8651816ea87a716f0fdc742e10a229523c67e7654433500f
font_02_sfnt_off0000ec5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC5F 16724 bytes
SHA-256: e72fb1281904e423a92afdff1e37d5edc3d24d22212d337b7c3a2b38fdc78a6a