Malicious PDF — malware analysis report

Static analysis result for SHA-256 77113b91aa0d3171…

MALICIOUS

PDF

76.1 KB Created: 2021-09-10 04:16:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9ab43e02ef22858e51be5a0ed9512f1f SHA-1: f2bfbcf6d0d2bef98f769c4d2855c6b1af224771 SHA-256: 77113b91aa0d317170465af5b6ef143ba4a5f1276fb1cacf5866b2cd6e78662c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://seikai.jp/free_images/files/gevexevotise.pdf In PDF document text
    • http://vetportonaccio.it/userfiles/files/nivolavajuv.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/c77092726ea6bed525bb6cb85d6afeb9/judevumerutonulotufado.pdfIn PDF document text
    • http://castudio.eu/userfiles/files/34471778441.pdfIn PDF document text
    • http://33podarka.ru/pictures/files/wosolunidepises.pdfIn PDF document text
    • https://samsungdvmklima.com/upload/ckfinder/files/wizexuvewawezozorosese.pdfIn PDF document text
    • http://foodzipo.com/uploads/userfiles/files/50375958148.pdfIn PDF document text
    • https://morganmethod.com/ci/userfiles/files/33686408831.pdfIn PDF document text
    • http://akbarestate.com/survey/userfiles/files/gesiwotaripesilaw.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210905070819.pdfIn PDF document text
    • https://autoroman-service.ro/imagini_ws/wobezibabopuvanapuxuz.pdfIn PDF document text
    • https://crcnueva.naturasoftware.com/uploads/images/files/8855425514.pdfIn PDF document text
    • http://amidoux-peintures.com/ckfinder/userfiles/files/siweduboselofibu.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/16133ae2faccce---2928379239.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/a38aa2e675e11d17d16240d32cbfc165/95720958912.pdfIn PDF document text
    • http://bnblspecialities.com/userfiles/files/86741728488.pdfIn PDF document text
    • https://xn----7sbbg1ddpkdc.xn--j1amh/uploads/files/kewakejalewera.pdfIn PDF document text
    • https://studiovizia.com/webroot/img/content/files/pevajenomof.pdfIn PDF document text
    • https://maxflowfans.com/userfiles/file/13325340610.pdfIn PDF document text
    • http://thriftstorewebsites.net/flash/thriftstorewebsites.net/file/44639599274.pdfIn PDF document text
    • http://anapharmata.hu/ckfinder/core/connector/php/files/60891001517.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=pubg+lite+new+latest+updatePDF 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_off0000bff6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFF6 19460 bytes
SHA-256: 3df6a3178534912be8c7ab5e0bcf9e0fea2cdb9f9315614fa2dcf3ef43d82822
font_01_sfnt_off0000f314.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF314 10676 bytes
SHA-256: 8998e4408de4ff1a4dcd2d5fe9d387c88e1fca7751454aaaebfc41db7f811aa1
font_02_sfnt_off00010b4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1