Malicious PDF — malware analysis report

Static analysis result for SHA-256 833646c570e50948…

MALICIOUS

PDF

83.7 KB Created: 2021-09-13 17:09:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 595545c296bea944fa92968d42652c11 SHA-1: acc2b7610844a65557fbd516d6ff605ef2a1dec3 SHA-256: 833646c570e509485180fb0463e8735239775911abf9e5df51e6c165eae4125d
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a ML classifier and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of a 'download snaptube app apk' URL, though marked benign, alongside other unknown URLs, points towards a potential phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://gdwtechnology.com/fckeditor/file/dikelozifi.pdf In PDF document text
    • http://www.keizerco.nl/userFiles/file/3654292829.pdfIn PDF document text
    • https://www.cdsale.org.au/application/third_party/ckfinder/userfiles/files/25412443591.pdfIn PDF document text
    • http://project-lovcen.me/userfiles/file/58475726297.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132934d70f38---kagujibojabowebipeliluges.pdfIn PDF document text
    • http://artdental.hu/editor_up/53377610010.pdfIn PDF document text
    • https://toolsatool.com/userfiles/files/20121159250.pdfIn PDF document text
    • http://andrelandberg.com/userfiles/file/51890857668.pdfIn PDF document text
    • http://chongthamphucthang.com/images/news/files/suwolawonekudozowexonada.pdfIn PDF document text
    • https://holcom-wd.holcom.vn/webroot/img/files/69883725938.pdfIn PDF document text
    • https://lucky-erotic-massage-bucharest.ro/ckfinder/userfiles/files/52646293128.pdfIn PDF document text
    • http://preprod.app-nomads.com/ugecam/admin/ckfinder/userfiles/files/47655935490.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161389486e5312---sefozukezigukog.pdfIn PDF document text
    • http://sattosushi.com/uploads/files/39514674305.pdfIn PDF document text
    • http://spc1991.com/ckfinder/userfiles/files/59044374209.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fa7fbc85c7---5889580204.pdfIn PDF document text
    • http://schuetzenfest-hemeringen.de/ablage/userfiles/files/61907835923.pdfIn PDF document text
    • http://www.psychophonie-tarbes.com/ckfinder/userfiles/files/nebipiro.pdfIn PDF document text
    • http://ms2oke.com/contents/files/sodonilamakojenogija.pdfIn PDF document text
    • http://mabifitness.it/userfiles/files/jofewib.pdfIn PDF document text
    • http://parfumerieindex.nl/images/uploads/fezujamox.pdfIn PDF document text
    • https://myarchitect.es/ckfinder/userfiles/files/26845647251.pdfIn PDF document text
    • http://marthomaiticherukole.com/userfiles/file/41575384400.pdfIn PDF document text
    • http://ntouioc.ntou.edu.tw/ckfinder/userfiles/files/nawixabapalofobedas.pdfIn PDF document text
    • https://led7.ru/file/86577238630.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=download+snaptube+app+apkPDF 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_off0000e30f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE30F 10612 bytes
SHA-256: 13ac395d39f80d80a232bd751d4d5f2b27e9d44270b0be47e0b10f2a0c3cc6f6
font_01_sfnt_off0000fb53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB53 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011365.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11365 17756 bytes
SHA-256: 81b45d2fa51e5cf6d302997cbb134790c2e4a0fb67247b4e7261dce8ea395b43