Malicious PDF — malware analysis report

Static analysis result for SHA-256 cc16ce23b4bb8d72…

MALICIOUS

PDF

82.1 KB Created: 2021-09-11 19:24:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 68d37f141db80362b373a2e9c5fbbf35 SHA-1: de339da17cd0d6a680e650e37bf8d55707b79de3 SHA-256: cc16ce23b4bb8d726222c17066579c59f95687fb44329511c96dd65d7c3e518c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the nature of the links and the PDF structure align with common phishing and malware distribution techniques.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://krisoc.ru/uplcv?utm_term=android+data+sharing+app PDF link annotation
    • https://tbsva.org/Upload/files/20210906061034.pdfIn PDF document text
    • https://cityface.cz/res/file/73037196144.pdfIn PDF document text
    • http://abworder.com/uploads/files/38795102622.pdfIn PDF document text
    • https://confeccionesruiz.cl/UserFiles/File/34018133939.pdfIn PDF document text
    • http://rasciindia.com/firetech/ckupload/files/jowemofujemusazosakoro.pdfIn PDF document text
    • http://jarosi.hu/files/file/jumonulerasage.pdfIn PDF document text
    • http://www.allatpatikapecs.hu/images/file/pixof.pdfIn PDF document text
    • http://sea-cruise.ru/ckfinder/userfiles/files/dopoketulowawuxukun.pdfIn PDF document text
    • http://pivotal-technologies.com/userfiles/file/subidemakajovu.pdfIn PDF document text
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16136d3b114469---jukaraninepuw.pdfIn PDF document text
    • http://castudio.eu/userfiles/files/56730231902.pdfIn PDF document text
    • https://lotte-ppta.net/beta/assets/file/zetugakuvolowogapev.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/16139edd4e4dff---61700150965.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139a44436d6c---83850760361.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/161369ad196fd4---27401214724.pdfIn PDF document text
    • http://boldogelet.hu/media/mamavukesafimededoxuxak.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/cd3330621e1808a8f85ca897c5318f11/22262162502.pdfIn PDF document text
    • http://helder-effect.nl/userfiles/file/mipanogabuli.pdfIn PDF document text
    • http://reklama-v-sochi.com/ckfinder/userfiles/files/sesawul.pdfIn PDF document text
    • https://hkbca.org/UploadFiles/file/20210910170629126.pdfIn PDF document text
    • https://receptabc.hu/images_banner/files/nugukebivimanixa.pdfIn PDF document text
    • https://derechosenred.org/aym_image/files/51718786515.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_off0000df02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF02 17084 bytes
SHA-256: 5723762928564ab7986503fd668d7466332db54e6eabc190e3b1bc719adb5b68
font_01_sfnt_off00010b28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B28 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001233f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1233F 10476 bytes
SHA-256: 886d24a5add60b50b37c088d4764941062d5f7e8a4fe0f33bada449f19f92eae