Malicious PDF — malware analysis report

Static analysis result for SHA-256 40fab8b806d017de…

MALICIOUS

PDF

69.0 KB Created: 2021-10-03 01:18:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 2bcd253ae4829784f1415cd44f6f52db SHA-1: c6896d05025ad551d7c9bfdb9520aa89d1e1a0a1 SHA-256: 40fab8b806d017debe5b3b70cecb17e339147b87b6e139b36860951d1f301ec1
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised websites, which in turn host other PDFs. This suggests a multi-stage attack designed to obscure the ultimate malicious payload. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://xn--b1akwe.xn--p1ai/userfiles/file/50188646301.pdf In PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/c359c7b07448a5a20086cfaa8e06be78/malemuwosananumudo.pdfIn PDF document text
    • http://wsm.hk/images/files/57830647479.pdfIn PDF document text
    • https://natanashoes.com/kingkong/userfiles/files/kemimaxexo.pdfIn PDF document text
    • https://www.potravinyav21.cz/ckfinder/userfiles/files/pomemebilus.pdfIn PDF document text
    • https://gitteszoneklinik.dk/ckfinder/userfiles/files/20996410157.pdfIn PDF document text
    • http://aotwcasino.com/ckfinder/userfiles/files/patasixalukovi.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/8fbe2b7e9bb99483cb7fd7c65760bb54/75253835395.pdfIn PDF document text
    • https://ln80.cn/filespath/files/20210902120552.pdfIn PDF document text
    • https://bienenaktuell.com/sites/bienenaktuell.com/files/file/puxutagowi.pdfIn PDF document text
    • http://nattuvaartha.com/assets/ckfinder/core/connector/php/uploads/files/pimezuzowax.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d672cb32b6---mepemogokibuniwolap.pdfIn PDF document text
    • https://thietkewebseo.com/webroot/img/files/kawefojozetugagajinilem.pdfIn PDF document text
    • http://tvsatkrosno.pl/userfiles/file/jositebekuginib.pdfIn PDF document text
    • http://shlawllc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dakaninobumobefo.pdfIn PDF document text
    • http://narnivet.com/userfiles/files/71268943999.pdfIn PDF document text
    • https://e-motorcycle.tw/upload/emotorcycle/files/57771417834.pdfIn PDF document text
    • http://huyminhplastic.com/upload/files/54362938662.pdfIn PDF document text
    • http://tnmetalworks.com/images/files/kuvane.pdfIn PDF document text
    • https://russiancosta.ru/ckfinder/userfiles/files/lakovusoluxux.pdfIn PDF document text
    • http://diversecityuk.com/userfiles/file/79455101645.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614b5fadb0706---18668671063.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=step+cut+with+layer+cutPDF 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_off0000adfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADFE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c610.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC610 16148 bytes
SHA-256: 79afe98ea594f5ef1b3a851532de8da7f4fe6946357f8b3b704fc7658cd5e4ce
font_02_sfnt_off0000eeda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEDA 10452 bytes
SHA-256: 1340731333e79700a11618cc188c20f04b9fea4e5e4fcac0f6467aea16838cfe