Malicious PDF — malware analysis report

Static analysis result for SHA-256 97c8b33387825222…

MALICIOUS

PDF

94.3 KB Created: 2021-09-05 07:15:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: f43f9389fb692407ec18e9b4458602dc SHA-1: d5a61412f5c0447c1814c10dcb8cb91e93556b7a SHA-256: 97c8b33387825222ea061c0053320811b244860d493a216bcc0fc492e5f282f8
96 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 WordPress sites, likely intended to host malicious files. The ML classifier strongly indicated maliciousness, and the presence of numerous external links on potentially disposable hosting supports this. No scripts were extracted, and the document body was unreadable, but the overall structure suggests a lure to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • 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://pianoinprimopianofestival.com/uploads/file/guzawedudegagorivudu.pdf In PDF document text
    • https://newtech-utm.pl/userfiles/file/mezab.pdfIn PDF document text
    • http://cmtoolsrental.com/user_img/files/kivorezokewuxagu.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608326ee12a9e---10576690496.pdfIn PDF document text
    • https://pindimana.in/uploads/file/zadirekikilovelen.pdfIn PDF document text
    • http://chetaomaynganhnhua.com/uploads/files/pisuvozimipedewodol.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/9393f5928a5b7a5eca35d442f854453e/xudenuwaji.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1607c2c4d02601---zudimagejifu.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e49bc4bac8---39296086379.pdfIn PDF document text
    • http://kartinatv.org/uploads/files/26743696282.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/fusawunukajifawufeka.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a8702ea9d13---vusasinenita.pdfIn PDF document text
    • http://inciboya.com/resimler/site/files/79978392791.pdfIn PDF document text
    • http://poliinc.com/upload/files/venanepote.pdfIn PDF document text
    • http://brukbet.com/user_images/file/87473186263.pdfIn PDF document text
    • https://samudra99.com/contents//files/16076696603.pdfIn PDF document text
    • https://www.couleurs-et-jardin.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607a38fc67ae4---51117156039.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16081951d84444---10931165299.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac0dd13ba3c---30650559114.pdfIn PDF document text
    • http://dush-kz.ru/uploads/fck/file/30868222109.pdfIn PDF document text
    • http://burrburroughsfamily.com/clients/55468/File/52630130237.pdfIn PDF document text
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/31ccc0a31e4525458ab0bc017a5c41be/38406635611.pdfIn PDF document text
    • http://zonwering-belgie.com/ckfinder/userfiles/files/25053657376.pdfIn PDF document text
    • http://barudan.hk/UploadFile/file/20210902231154402.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=indirect+democracy+pdfPDF 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_off00010935.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10935 10632 bytes
SHA-256: be6127fba377d6bcfce1094e4b04fdcc2116bbc2e1787efd1718632cd3f34880
font_01_sfnt_off0001217e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1217E 19348 bytes
SHA-256: 3243d570cb00282ca2fd1bf08a1cc16355a27c3f2d37294779b1177877aa653c
font_02_sfnt_off000153a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x153A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1