Malicious PDF — malware analysis report

Static analysis result for SHA-256 511f18e0dd5b6ca4…

MALICIOUS

PDF

84.5 KB Created: 2021-09-16 16:14:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 83a0cdc7f0d6e89dabf840a85d76fa11 SHA-1: f11dfd7577400b2a59b2674684052cad706a978b SHA-256: 511f18e0dd5b6ca4c1f3b332a451833c56c565c4bfac9bb91a333ce53ddfa20b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. The document also functions as a link farm, directing users to multiple external URLs hosted on compromised or disposable domains, likely to facilitate phishing or download further malware. The presence of these elements strongly suggests a malicious intent to compromise the user.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • 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://archism.ru/uplcv?utm_term=imls+ml+apk+latest+version PDF link annotation
    • http://musthighschool.mn/ckfinder/userfiles/files/wisujitasu.pdfIn PDF document text
    • http://interface-referencement.com/userfiles/file/40882637247.pdfIn PDF document text
    • https://maggies-handmade.com/UserFiles/files/nelatesinazola.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e96dd41257---95413252154.pdfIn PDF document text
    • https://arichaindia.com/userfiles/file/8647488340.pdfIn PDF document text
    • https://sibservis.com/ckfinder/userfiles/files/gurarifamimilun.pdfIn PDF document text
    • http://htbestcomputer.com/media/ftp/file/zojofefokok.pdfIn PDF document text
    • https://fullgame.hu/uploads/files/dewutipenolak.pdfIn PDF document text
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1614113b360e2b---xarumose.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142a27e73d29---38100435276.pdfIn PDF document text
    • http://thibangoto.com/app/webroot/uploads/files/7865781108.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/b7rmacejebos4bll2q9o3slhc7/5234121945.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613d985aab6e2---borubulusibuxoguvajiteson.pdfIn PDF document text
    • http://longbienco.com/js/ckfinder/userfiles/files/gevinapomisewo.pdfIn PDF document text
    • http://talesma.com/E/file/nafopudoluzos.pdfIn PDF document text
    • http://naitikfashions.com/ckfinder/userfiles/files/83542315759.pdfIn PDF document text
    • http://naitikfashions.com/ckfinder/userfiles/files/4478137149.pdfIn PDF document text
    • http://tzoetemondje.be/uploads/files/gamelepegexakila.pdfIn PDF document text
    • http://nassagroup.org/app/webroot/js/ckfinder/userfiles/files/fizovisikilidurum.pdfIn PDF document text
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/0341aa5260faf136a0db5cff87cdff19/38900129361.pdfIn PDF document text
    • http://modulobase.com/userfiles/file/lejadobenefirajoxitiromip.pdfIn PDF document text
    • http://downtowncincyhotels.com/core_degree/admin/images/cms_imagesfiles/rabufevaran.pdfIn PDF document text
    • https://xpress2.eu/ckfinder/userfiles/files/22992462573.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/161314587e5a12---lapirulifiregezax.pdfIn PDF document text
    • http://bloemenwinkelindex.nl/images/uploads/jusetegufobumirobudefiwe.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_off0000e628.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE628 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE3F 10524 bytes
SHA-256: e04fa38757a3d02c49c2d23080f51b6bae34b3d2744a7f3e77916d7f7fd5de5c
font_02_sfnt_off00011634.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11634 17836 bytes
SHA-256: 9e1171beb5890f95585ba47b15d6629fa1571719f17194c47f2c77d6f64a1130