Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac728479668142c4…

MALICIOUS

PDF

85.4 KB Created: 2021-09-18 21:09:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1d1768e3b2e304f32ae54721a0ba20e0 SHA-1: 1eeffbad69769db225a9617d9e63f144db57cf03 SHA-256: ac728479668142c46c78166f6b9be4e8ab8a351115c91b14c6cbfdff6404cdad
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a malicious PDF detected by ClamAV and an ML classifier, containing embedded JavaScript. It functions as a link farm, directing users to numerous external URLs, many of which are hosted on compromised or disposable domains. The embedded JavaScript likely facilitates the redirection or further exploitation, contributing to a phishing or malware distribution scheme.

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://laborke.ru/uplcv?utm_term=dazed+and+confused+123movies
    • https://facades-et-traditions.com/actualites/file/21202510555.pdf
    • http://k-ookuma.com/js/upload/files/petedekovolupeboxoliduzi.pdf
    • https://medosojewellery.com/userfiles/files/momito.pdf
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/aach5sp04ikvfmh94uif209a89/30078459117.pdf
    • https://dimensioninteractive.com/WYSIWYGImage/file/jenofisujuteridixo.pdf
    • http://landia-print.com/pdir/file/13186803933.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132c21b7aa26---87402122584.pdf
    • http://nifaelectronics.com/userfiles/file/sugilejokunirovilivirezis.pdf
    • http://www.gieskestukadoors.nl/ckfinder/files/files/15111819894.pdf
    • http://vigova.vn/Images_upload/files/tuxag.pdf
    • https://drlanda.hu/user/file/34497910046.pdf
    • http://xn--or3bi2da319p.com/upload/fckeditor/file/85244915074.pdf
    • http://bitree.net/ckfinder/userfiles/files/bebasovemivuniv.pdf
    • https://gulamanis.com/contents/files/dulibenukujow.pdf
    • http://lamardaegu.com/upfile/user/file/37067763030.pdf
    • http://ekhoron21.mn/uploads/files/puwuwipevapam.pdf
    • http://plafondchauffant.fr/img/user/file/42621334722.pdf
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/cc107833d1ac54f5716d34cd359fa944/9898358675.pdf
    • http://teewer.mn/ckfinder/userfiles/files/rikilonuzadamimipikafi.pdf
    • http://fusen-es.info/yamituki-n/uploads/files/suvepogeladukutaxix.pdf
    • http://ksklinika.ru/ckfinder/userfiles/files/sebix.pdf
    • http://sbriz.ru/userfiles/file/90049038083.pdf
    • https://www.jancsoalapitvany.hu/ckfinder/userfiles/files/bulep.pdf
    • http://andreuma.madteam.net/ckfinder/userfiles/files/birozug.pdf
    • http://cosmikkino.ru/sadm_files/gakosulam.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e41d.bin
6f4b2001f5379d494b69edee8d835319561305f8ce20a3dc6b81cefec205e832
pdf-font-stream PDF embedded font (sfnt) at offset 0xE41D 10964 bytes
font_01_sfnt_off0000fdbb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFDBB 16792 bytes
font_02_sfnt_off000115cd.bin
a7d799165372bf7ae1a8220b16082f5d02e5406287a3b26f06d97be9bd8d4057
pdf-font-stream PDF embedded font (sfnt) at offset 0x115CD 19168 bytes