Malicious PDF — malware analysis report

Static analysis result for SHA-256 5bf80a209638330a…

MALICIOUS

PDF

75.5 KB Created: 2021-09-03 01:09:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: aea99790648b8ef364a544e6830d14d4 SHA-1: b3a372051b93cb39230018f357d619493b0b4311 SHA-256: 5bf80a209638330a31f9592b5f436b753bf7edc59287b29126f6e58d80da3b41
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with multiple URLs pointing to potentially compromised or disposable hosting. The presence of numerous PDF links suggests an attempt to direct users to external, untrusted resources, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://danielstrehlau.com/userfiles/file/zofifoboxamokikudu.pdf In PDF document text
    • https://kompaspt2.com/contents//files/11619257723.pdfIn PDF document text
    • https://www.acetechnology.co.in/wp-content/plugins/super-forms/uploads/php/files/lbdl8hhdpjfetosie463i1sqil/melesokitononivotu.pdfIn PDF document text
    • http://sanphamhanquocymy.com/uploads/files/71566735165.pdfIn PDF document text
    • https://gitteszoneklinik.dk/ckfinder/userfiles/files/68185318983.pdfIn PDF document text
    • http://bruisedreedfoundation.org/clients/4/4d/4d9d7eec3bf3a09fa0457ace138f6a4e/File/sadidiguzinukes.pdfIn PDF document text
    • http://macabrey-luthier.fr/data/Files/jofetado.pdfIn PDF document text
    • http://guojingmall.com/userfiles/file///7666547537.pdfIn PDF document text
    • https://www.domaine-boussard-chablis.fr/ckfinder/userfiles/files/1295468986.pdfIn PDF document text
    • https://arizonalightingsales.com/wp-content/plugins/super-forms/uploads/php/files/07e48be6f9b57ebf3ba57f381fd8c5ed/44436090746.pdfIn PDF document text
    • http://diakmelo.hu/ckfinder/userfiles/files/26654096340.pdfIn PDF document text
    • https://www.sadcmedia.com/wp-content/plugins/super-forms/uploads/php/files/ibiitc14jj4rrre04l2ca2st57/sokorinobogufupal.pdfIn PDF document text
    • http://bjbtrh.com/files/pic/file/xudawenosususefosokavi.pdfIn PDF document text
    • http://win-sonic.com/kida2018/ck_imgs/files/20526139230.pdfIn PDF document text
    • http://globeksa.com/ckfinder/userfiles/files/gaxano.pdfIn PDF document text
    • https://brawlcall.com/ckfinder/userfiles/files/faxibonatokovowo.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16081cd4303ed9---fadoxelanefinigewo.pdfIn PDF document text
    • https://kcharp.com/ckfinder/userfiles/files/fufuzodoxasiduzobi.pdfIn PDF document text
    • http://photonart.nl/phpcmsys/file/97247323037.pdfIn PDF document text
    • http://0048.pl/48files/file/fosugaravisuvimimu.pdfIn PDF document text
    • http://ac-kenigsberg.ru/files/file/kuwiguruwugumafidedaledo.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/1607ebef586b52---85451205830.pdfIn PDF document text
    • https://alkirbilaw.com/userfiles/files/zukukigiko.pdfIn PDF document text
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160879e244716a---91485163920.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=literary+essay+outline+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_off0000c4fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD0E 16588 bytes
SHA-256: 32be8059b4de732b9475efc97d73b62c290bb39fc1fc10ed91c4f63f8a112223
font_02_sfnt_off000107d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107D6 10660 bytes
SHA-256: 9d8488f0369a420380c9a2f2c1d425f3b0487b5e53f88e92531368da7ac2288c