Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb15a2882f59b8a7…

MALICIOUS

PDF

71.0 KB Created: 2021-09-26 22:26:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: c895fea2fdb3ca5894e9023acb8ca562 SHA-1: 0700f875416d9340c0f3196f53da5537b6863511 SHA-256: cb15a2882f59b8a7752c8acdaf5f3d3f3d721dfb94024e8e2ca69e4a7aff3cda
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The heuristics identified the document as a link farm, with numerous embedded URLs pointing to various PDF files hosted on different domains. The primary purpose appears to be SEO manipulation or distributing further malicious content through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://rosycaffe.com/file/navipiruximusajizonateba.pdf In PDF document text
    • http://radecznica.pl/userfiles/file/jojomodolunopuzizezavozot.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613292bf3535c---89718198174.pdfIn PDF document text
    • https://dhrc.in/userfiles/file/39162807777.pdfIn PDF document text
    • http://avandcie-automation.com/ckfinder/userfiles/files/lerovinixogedew.pdfIn PDF document text
    • http://thanhtindesign.vn/uploads/image/files/wexomelivuvowadetopuzi.pdfIn PDF document text
    • http://tovicetour.com/FileData/ckfinder/files/20210903_F35358DA167DD5FA.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c920a812e2---wijorowepavisofamolamemo.pdfIn PDF document text
    • https://mimpishio1bet.com/contents/files/mowarulovurelanoxem.pdfIn PDF document text
    • http://xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/32597088608.pdfIn PDF document text
    • https://alemarferries.alemarsnp.gr/ckfinder/userfiles/files/nevitewoxuzazobuwuliga.pdfIn PDF document text
    • http://filipdegreef.be/uploads/files/vedafasetotogafu.pdfIn PDF document text
    • https://hanakspotrebice.cz/eshop/ckfinder/userfiles/files/93166499161.pdfIn PDF document text
    • http://www.astmalek.cz/obrazky/file/batejavowavimizi.pdfIn PDF document text
    • http://chongthamnguoc.vn/img/files/36872120854.pdfIn PDF document text
    • https://sushixusa.com/userfiles/files/taguxakefekomid.pdfIn PDF document text
    • https://ost-fogging.com/upload/files/vikudepizibunakezuzadu.pdfIn PDF document text
    • http://kamerton.nl/clientfiles/75866136165.pdfIn PDF document text
    • http://iphonedown.com/ckfinder/userfiles/files/10527687856.pdfIn PDF document text
    • http://lnaixi.com/userfiles/file/20210926070917_1608959296.pdfIn PDF document text
    • http://ergo-logo-bamberg.de/userfiles/file/83844102088.pdfIn PDF document text
    • https://tarzminder.com/resimler/files/xajazizo.pdfIn PDF document text
    • http://www.startservis.sk/novy/ckfinder/userfiles/files/voradoniniba.pdfIn PDF document text
    • https://kiaavcilar.com/upload/ckfinder/files/punalolidojojid.pdfIn PDF document text
    • http://istihdamhaberleri.com/upload/ckfinder/files/11991205068.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=remote+control+pc+from+androidPDF 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_off0000b38f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB38F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cba6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBA6 10660 bytes
SHA-256: ac2eaf5be55e4ade1c402fe82529d5020693aab752ac9b2f29645c30ec830d1c
font_02_sfnt_off0000e3f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3F9 16652 bytes
SHA-256: 583c7a437ebb710142ddb6b49118b86f735a99246711b4eada3a1d74466058a5