Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb83f8d27ec041fd…

MALICIOUS

PDF

81.9 KB Created: 2021-09-19 08:51:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6006ed445777a42e01d5aa765f14248d SHA-1: b3f5245a598db1edba20083b1d7f95c20e7983c8 SHA-256: fb83f8d27ec041fd1c7e4bdb5be08ffd6fb291e7015b8183b6f659a5f6da9f58
126 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous embedded URLs, with a heuristic identifying it as a link farm on disposable hosting. The primary purpose appears to be directing users to a collection of other PDF files hosted across various domains, likely for SEO manipulation or to distribute further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146b92c53571---xulujojuxegape.pdf In PDF document text
    • http://rwdwebwebdesign.com/img-aim/files/siminejelumipotikove.pdfIn PDF document text
    • http://thcsducthang.pgdbactuliem.edu.vn/ckfinder/userfiles/files/tamexole.pdfIn PDF document text
    • http://micruts.org/userfiles/file/fimamogobu.pdfIn PDF document text
    • http://protetyka-lublin.com/images/wyswig_images/file/53600079299.pdfIn PDF document text
    • https://braindevelopmentmaps-org.neurondevelopment.org/userfiles/files/62536392850.pdfIn PDF document text
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/161412b13b648f---mulezotew.pdfIn PDF document text
    • http://softwarefactory.nl/images/file/rerobimomofebebi.pdfIn PDF document text
    • https://groupunsur2.com/contents/files/61761052266.pdfIn PDF document text
    • http://xn----dtbsgbucafmmaf.xn--p1ai/servimages/editor/files/musevulexuwu.pdfIn PDF document text
    • https://ww150002.linebot.net/upfile/files/20210916165132.pdfIn PDF document text
    • https://tempatpasang.com/contents/files/24164590540.pdfIn PDF document text
    • http://henskeschildersbedrijf.nl/upload/positifabalepimelivitisad.pdfIn PDF document text
    • http://badischer-kunstverein.de/ckfinder/userfiles/files/rorelolefuw.pdfIn PDF document text
    • http://montagnobozzone.it/userfiles/files/99667626051.pdfIn PDF document text
    • http://traiteur-ribot.fr/userfiles/file/52272853609.pdfIn PDF document text
    • http://client.diffuse.info/files/kegetefaxurogano.pdfIn PDF document text
    • https://www.orthovision-lublin.pl/ckfinder/userfiles/files/dafavabiludagizova.pdfIn PDF document text
    • http://greenhere.cn/upload/ckimg/files/202109171659043308.pdfIn PDF document text
    • https://masihpt2.com/contents/files/39403499331.pdfIn PDF document text
    • http://facyt.com.ar/ckfinder/userfiles/files/70605012335.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=what+is+best+ios+or+androidPDF 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_off0000dddd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDDD 17256 bytes
SHA-256: d5e9645fe7f4b1ab453c7acc0f0e7006859d37c693f8879ec78ca6e74a81f633
font_01_sfnt_off00010a9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A9B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000122b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122B2 10432 bytes
SHA-256: ce084c4ce9bbfdcc86d1d68e06ba08f2d8dfe0210af1cb0dceafc6fd32ad4281