Malicious PDF — malware analysis report

Static analysis result for SHA-256 16dcedfac10f0b57…

MALICIOUS

PDF

70.3 KB Created: 2021-09-16 19:00:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: d71dbbb0737d22116478c8ffcd5e9b0c SHA-1: 67e1a45543af51e0dc9c0d49763652670d5cae8e SHA-256: 16dcedfac10f0b57ad20f4bcf33baf0babd6478efa1dd778d16bf45f7a598bfd
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to disposable hosting or compromised CMS upload directories, suggesting it functions as a link farm. These links likely lead to phishing pages or further malware downloads, aligning with the 'Spearphishing Attachment' and 'Exploitation for Client Execution' techniques.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://smidgel.ru/uplcv?utm_term=traffic+race+3d+game+free+download PDF link annotation
    • http://flyingwedge.com/uploads/assets/file/xexasesini.pdfIn PDF document text
    • https://mahanakhon.pacedev.com/ckupload/files/77945727583.pdfIn PDF document text
    • http://diversecityuk.com/userfiles/file/54492706518.pdfIn PDF document text
    • http://hzqljsj.com/images/upload/File/kukawabagerasagamifu.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613275bf74638---mazokazezewaxeduberekos.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/bdf485859fb6c303dfa49752d4e267f9/xeton.pdfIn PDF document text
    • https://ysh.my/userfiles/file/49958611088.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613e6ec11b930---vufifagafamejukonipijix.pdfIn PDF document text
    • https://bitree.com/ckfinder/userfiles/files/dekeliwu.pdfIn PDF document text
    • http://girisimcilikproje.com/resimler/files/wotutunutigogubeg.pdfIn PDF document text
    • http://smcertificationservices.com/userfiles/files/43172740985.pdfIn PDF document text
    • http://palami.by/images/file/48643258868.pdfIn PDF document text
    • http://saxonrt.hu/img/userfiles/files/3747715609.pdfIn PDF document text
    • https://digireg.nz/upload/fazamezusugoluju.pdfIn PDF document text
    • http://honghuibio.com/d/files/zijasawisenifagenujotelat.pdfIn PDF document text
    • https://alpinashop.rudy-ra.com/files/46474340845.pdfIn PDF document text
    • http://atek-ent.com/upload/file/sezuvuxokuwe.pdfIn PDF document text
    • http://praguynakorn.com/praguynakorn/picture/datapro/files/4674875273.pdfIn PDF document text
    • http://weldingplaza.com/files/file/muluf.pdfIn PDF document text
    • https://cornerstonelaw.eu/userfiles/file/81013622429.pdfIn PDF document text
    • https://ordermorestuff.com/cmsCart/upload/file/67312951608.pdfIn PDF document text
    • https://badrivishal.com/media/67957651350.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_off0000b3d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3D4 15496 bytes
SHA-256: 64e1d157487d818663e4b03976ba777807fe5800d18abac6c4219f43d14fd385
font_01_sfnt_off0000db3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB3B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f352.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF352 10772 bytes
SHA-256: 9b69eb49a06f5b30108178dcd2b85f5dfd68d99ea587dd5055ad187b7dd6ec6a