Malicious PDF — malware analysis report

Static analysis result for SHA-256 5e31fa2b1959deae…

MALICIOUS

PDF

82.6 KB Created: 2021-09-17 13:37:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: a8f5919a71db46b88e9364100d6a25fc SHA-1: 3903b57ec80d19d0d4501a31001a3e242f4c0f32 SHA-256: 5e31fa2b1959deae464934f248b9e1519bf025f458dc217aefe26f4b4af001c9
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, with a high heuristic score indicating it functions as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were directly extracted, the PDF structure and embedded links point towards an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://inciboya.com/resimler/site/files/dekemukewizamenuz.pdf In PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/161407a5497bde---31311255696.pdfIn PDF document text
    • http://cablexconsulting.com/Upload/file/82164886364.pdfIn PDF document text
    • https://okazdedziecko.pl/_files/Media/file/jasusovinezaxegejanexenum.pdfIn PDF document text
    • http://hotelborgodeipoeti.com/userfiles/files/48116126457.pdfIn PDF document text
    • http://tdsns.ru/userfiles/file/53995870572.pdfIn PDF document text
    • http://fairbank-ia.org/admin/ckfinder/userfiles/files/xemobirorazaxatidikuw.pdfIn PDF document text
    • https://lifesmart.lifesmart.ro/ckfinder/userfiles/files/biromepowokuwesotosaro.pdfIn PDF document text
    • http://metaglas.kr/userData/board/file/parujuvesowitaripo.pdfIn PDF document text
    • http://crystaltrade.hu/data/file/vowoxowigod.pdfIn PDF document text
    • https://cahayamimpi1.com/contents/files/34953480657.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/161378fc5ad3ff---81703228457.pdfIn PDF document text
    • https://artenika.pl/fck/file/jovoximerabowesabuwo.pdfIn PDF document text
    • http://brixtontaxi.com/survey/userfiles/files/14319780790.pdfIn PDF document text
    • https://www.wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/relijaj.pdfIn PDF document text
    • https://grdr.org/paidel/ckfinder/userfiles/files/9347940703.pdfIn PDF document text
    • https://cuatudongnhatrang.com/uploads/files/74324036334.pdfIn PDF document text
    • https://sunrise-photon.com/upfiles/editor/files/kanoj.pdfIn PDF document text
    • http://sz-nuoyi.com/Upload/file/2021091308561424925.pdfIn PDF document text
    • http://cdseoulps.com/uploadfile/fckeditor/file/15569624259.pdfIn PDF document text
    • http://upoart.com/ckfinder/userfiles/files/7344446261.pdfIn PDF document text
    • http://northmarking.com/userfiles/files/73449836404.pdfIn PDF document text
    • http://ramenhajimetustin.com/uploads/files/5849483161.pdfIn PDF document text
    • https://szalkasszorutacskok.hu/app/webroot/files/content/files/xopodazerazedejadikatej.pdfIn PDF document text
    • https://baglab.pl/galeria/file/zinalunoraju.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+delete+android+apps+that+came+with+phonePDF 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_off0000dc21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC21 10856 bytes
SHA-256: 51e8950cd196d578297c0de8a126ab7253f2c9757f2f54b51b34b5107716129a
font_01_sfnt_off0000f4fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4FB 18168 bytes
SHA-256: 9e38730df8cab8bc4e50119678de6da8e13d2fdc343781e5d63de1b5e1270362
font_02_sfnt_off000123f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1