Malicious PDF — malware analysis report

Static analysis result for SHA-256 3122c1684f53eeeb…

MALICIOUS

PDF

74.3 KB Created: 2021-09-08 11:24:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e600f00c739c4936dd282d8caed961ba SHA-1: 71fec72d0e0a3c7c727ec55fe6bff707cc018372 SHA-256: 3122c1684f53eeeb0c773767fc6d9af4b9fef9f27b1f368100a705401825d891
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs pointing to compromised WordPress sites and disposable domains, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the heuristic findings suggest it is part of a link farm strategy. The primary goal appears to be directing users to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://huntic.ru/uplcv?utm_term=medicinska+mikologija+pdf PDF link annotation
    • http://kqcme.yiaiwang.com.cn/upload/files/toxolim.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bec57e20df7---xakifapawufasaxezino.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b2c7f2b1ba---kubogaganedemozexev.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/16080bd049ba7b---varofetunedezuka.pdfIn PDF document text
    • http://dharmapuridiocese.com/svnprojects/DHD/Source/images/files/kujijuno.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/160cac4e1aa5e3---6891356661.pdfIn PDF document text
    • http://studioscoponi.eu/userfiles/files/lebupimug.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160dbb8d457d1a---rolomukotaxavajulupotiw.pdfIn PDF document text
    • http://prociweb.hu/sites/files/file/kuxol.pdfIn PDF document text
    • https://anmoul.com/userfiles/file/76150002385.pdfIn PDF document text
    • http://www.jokilaaksonratsastajat.fi/file/81682976896.pdfIn PDF document text
    • https://aimhc.com/userfiles/file/dugazuj.pdfIn PDF document text
    • http://jan-fotografie.nl/upload/files/69264034974.pdfIn PDF document text
    • https://mwasafat.com/uploads/files/vimabakasewomulefijis.pdfIn PDF document text
    • http://www.yankey.com.tw/demo/public/editor/ckfinder/upload/user_upload/files/87594505142.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609128b250798---rasidag.pdfIn PDF document text
    • https://pjkconstruction.ca/images/file/87593006943.pdfIn PDF document text
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e29abc5b52---kepowaxerorapogiguxulofun.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137b67374a9e---64438913549.pdfIn PDF document text
    • http://meta-min.com/files/nuvikijirokawukav.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/4b51a302ad1860af987af76e674aa9ad/kebesudofijokiv.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/5250e5087fa98406cf8f5c6fd0d06d2e/pefisovunadediwalok.pdfIn PDF document text
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/2d6feaf8acbb7221dc7505f223ebb56a/18216605784.pdfIn PDF document text
    • https://advik.net/userfiles/file/84858929616.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e60cbfc818d---10570131646.pdfIn PDF document text
    • 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_off0000be98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE98 16928 bytes
SHA-256: be318b974d812598ab525d554cee788aef58750df26436b69bc20f57e19ccf53
font_01_sfnt_off0000ea47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA47 10980 bytes
SHA-256: f3399afb7dbd57ec3c6991264f112f9194799ddc6314a6da3d67341c6ba125b8
font_02_sfnt_off0001037a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1037A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1