Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d638da052d1d224…

MALICIOUS

PDF

79.5 KB Created: 2021-09-19 07:08:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 3aea82f06f0ca3bfdc6ebf63e9888adf SHA-1: 4c61c6115dfeb1ceda99dc261577b645d9a3f528 SHA-256: 8d638da052d1d22494b3cc4db22504dd34fd3fc2f754fa86eb6530d2727d296d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of link farms hosted on compromised or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is likely responsible for redirecting users to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://pistant.ru/uplcv?utm_term=minecraft+for+free+ios+no+jailbreak PDF link annotation
    • http://nhanvietgroup.com/demo/xay-dung-tnx/upload/files/9612271354.pdfIn PDF document text
    • https://cottingham-group.com/cufiles/files/butopuw.pdfIn PDF document text
    • http://sieuthicayxanh.vn/webroot/img/files/49496326893.pdfIn PDF document text
    • http://xatrbio.com/userfiles/file/bidum.pdfIn PDF document text
    • http://machulski.com/public/file/vutamapejanilumodomawa.pdfIn PDF document text
    • http://softwaretesting.kr/club/data/userfiles/file/20210906114200.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/jlkcik80pmp936nj73q7tbfh43/95981030852.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/abdf597e019591f1f4d5980fcf980661/80249873754.pdfIn PDF document text
    • https://equalland.com/uploads/File/pakesoturitileporupi.pdfIn PDF document text
    • http://konberdbio.com/upload/files/7978812524.pdfIn PDF document text
    • http://saltokisport.com/uploads/files/42534626417.pdfIn PDF document text
    • http://marta-galan.com/files/varios/file/9475743840.pdfIn PDF document text
    • http://refpecsbelvaros.hu/kepek/files/61339669983.pdfIn PDF document text
    • http://mackyz7automotive.com/js/upload/files/garuvemirutosuj.pdfIn PDF document text
    • http://foodzipo.com/uploads/userfiles/files/92199296635.pdfIn PDF document text
    • http://sakem.org/userfiles/files/60983296652.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/16139496ccd1e1---pokug.pdfIn PDF document text
    • http://effektfilm.de/files/file/kikapidabafo.pdfIn PDF document text
    • http://abarappresentanze.it/userfiles/files/jirarixujuvojureboba.pdfIn PDF document text
    • http://seoulmenu.com/uploads/files/jisafanozutaj.pdfIn PDF document text
    • http://pro-group.ru/userfiles/files/95072764257.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_off0000ce85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE85 10684 bytes
SHA-256: 6e5fd5f828a736bb29e4da996f9ab1858184172755b37b0f208fb0b04b38113b
font_01_sfnt_off0000e71d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE71D 18784 bytes
SHA-256: 698e728692d2b5ea6929d738ee2478520b075b629700a4dac40cf0bc8ec8d9d5
font_02_sfnt_off0001181e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1181E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1