Malicious PDF — malware analysis report

Static analysis result for SHA-256 c79302342978f83f…

MALICIOUS

PDF

83.6 KB Created: 2021-07-22 20:58:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 499645beab45c081b2d153b40dcb2311 SHA-1: 303717af8f1ba2efa7acd19322f6358c8bdc7266 SHA-256: c79302342978f83f89fee70bf27a5667637148b6e7a72e01073dcfe2dceeaeea
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains a link farm, directing users to numerous external URLs, several of which are hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution via these links. No scripts were extracted, and the document body was unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://susta.vn/userfiles/file/kevixawedoji.pdf In PDF document text
    • http://studiomarazzi.eu/userfiles/files/7125475721.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/100009458791.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608daff66cf96---buzagokilufal.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/7c611c9a1f073cdc0f7738e0cf412fa5/9051486692.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082dd965116b---fuwawifilamejazixu.pdfIn PDF document text
    • http://penzionriverside.cz/files/file/63627253731.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a26a4b56825---96251076916.pdfIn PDF document text
    • http://grafiport.com/userfiles/file/64961453562.pdfIn PDF document text
    • http://nfrostov.ru/upload/files/renopirivozaxufulitudolif.pdfIn PDF document text
    • http://thunderstar.cn/userfiles/file/20210629152655100260350.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/6d70f1814bc9b3024969df7ae50bf47b/69359833184.pdfIn PDF document text
    • http://rc-modeller.se/images/file///supalaluvokirixax.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/l37q19c92g4lagrhi3entbhcfe/3912894012.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091696b9e68b---6455292246.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607851bf5dd12---97205578870.pdfIn PDF document text
    • http://clinicaveterinariagussago.com/userfiles/files/31790719366.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b6049beb1c0---bovotolewaxumega.pdfIn PDF document text
    • https://t2sc.me/userfiles/83276697487.pdfIn PDF document text
    • https://rubyyadav.com/nbloom/fckuploads/file/6534708213.pdfIn PDF document text
    • https://kabelkyaobuv.sk/editor_uploads/files/97419892563.pdfIn PDF document text
    • http://tfh-filter.hu/_user/file/82229678693.pdfIn PDF document text
    • https://alternativecarrepair.com/userfiles/file/rikonixobumiri.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c2efbf3b77c---88724668188.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=what+did+we+learn+in+2020PDF 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_off0000e60b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE60B 10376 bytes
SHA-256: 67e02eb5b9897819ed266951c6a9427f71300887a144cb0cd7cbb4d87cc81cc5
font_01_sfnt_off0000fd85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD85 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011597.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11597 16600 bytes
SHA-256: 0cfaa2d728836d74cdce68c2d7a9fe78023035def468b9f9ea3daebc06472061