Malicious PDF — malware analysis report

Static analysis result for SHA-256 a572867f5f1b96d3…

MALICIOUS

PDF

83.4 KB Created: 2021-09-23 23:59:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ce6b81a0d9b996bb1e1261e198b603e9 SHA-1: a293dde51c2a1a67bf3f6500a36ab0177c404c80 SHA-256: a572867f5f1b96d344f222a0ae75531bdc2b6c6c30910ffbf48908408affe1f9
166 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, with high-severity heuristics indicating the presence of algorithmically generated URLs and a link farm hosted on disposable domains. The document body is heavily obfuscated, preventing analysis of its specific content, but the numerous external links suggest a phishing or credential harvesting attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://hzzxtl.com/UploadFile/file/20210921103422017.pdf In PDF document text
    • http://mya1fc.com/files/ckuploads/files/dusabegilonafiwabel.pdfIn PDF document text
    • http://domainecomps.com/documents/files/89737711936.pdfIn PDF document text
    • https://rusepress.com/uploads/wysiwyg/files/zugaroz.pdfIn PDF document text
    • https://dpdpunjabi.myskoolapp.com/FCKeditor/FCKimgUpload/file/bupakali.pdfIn PDF document text
    • http://oralrem.kz/ckfinder/userfiles/files/3779494119.pdfIn PDF document text
    • https://eliteplacementagency.com/uploads/files/18791974450.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614cc1419b40d---68258496846.pdfIn PDF document text
    • http://phoiinnhiet.com/images/uploads/files/55984678646.pdfIn PDF document text
    • http://jtylek.pl/Upload/file/35931047886.pdfIn PDF document text
    • http://studiolauramoschini.it/userfiles/files/zufefizume.pdfIn PDF document text
    • http://bangdinhphucat.com/quangbasanpham/app/webroot/upload/image/files/dovivuzosekozuz.pdfIn PDF document text
    • https://childrencareandliteracysociety.org/userfiles/files/1070364575.pdfIn PDF document text
    • http://cuanhuadanang.vn/uploads/image/files/56789300723.pdfIn PDF document text
    • https://xlspandoek.nl/userfiles/file/novidilibona.pdfIn PDF document text
    • http://www.fishandcosolicitors.com/uploads/files/wunakapi.pdfIn PDF document text
    • http://mrs-edu.com/sribati/editor/uploadfiles/4707465814.pdfIn PDF document text
    • http://sanruou.com/app/webroot/uploads/files/19604283335.pdfIn PDF document text
    • http://getrade.net/uploadfiles/file/dubarisejawozevir.pdfIn PDF document text
    • https://bibonatura.hu/ckfinder/userfiles/files/43087174796.pdfIn PDF document text
    • http://studiopiergentili.it/userfiles/files/7676088175.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/0c1a660e4e787ee842c21da721152c68/porapubideni.pdfIn PDF document text
    • http://knauto.com/upload/file///37199362243.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=how+to+get+minecraft+apkPDF 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_off0000e186.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE186 17484 bytes
SHA-256: 75258d138548565185ff96d3fc473293cb3443be5285bafd44837c3558cc6c41
font_01_sfnt_off00010ee9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EE9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012700.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12700 10776 bytes
SHA-256: b6a898fa7574037a523e4eaadf25b6213c371eba78c593104a23b3c2b532a136