Malicious PDF — malware analysis report

Static analysis result for SHA-256 99a427d8461b40d1…

MALICIOUS

PDF

97.7 KB Created: 2021-06-26 12:43:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fb6b036528d8020ef064821008781523 SHA-1: 397ef92a020c8df125d93e9b9e0d26c1cab15454 SHA-256: 99a427d8461b40d161fdd670503fc7514d58945e4aad0f232c7d29631dfa10f5
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to various domains, many of which are hosted on compromised CMS platforms or appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is obfuscated and does not provide direct textual clues, but the heuristic findings are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9800

Heuristics 6

  • 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.
  • 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://jncs.kr/page_data/file/20210603190206.pdf
    • http://jyotiacademicpress.org/uploads/file/3624742166.pdf
    • http://computerdoki.hu/user/file/juxixipupemosobaxawuxe.pdf
    • https://alutat.com/data/file/61828747252.pdf
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0d7873526a---rakarojirukagopopobi.pdf
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/e3c891026e3f3748f3faf9425859db1f/toxujerozajivuresis.pdf
    • http://ubest.ru/images/file/sositefe.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c36bf94ec7c---nidonatefaj.pdf
    • http://simonide.org/userfiles/file/ziborudikekajevijibegewu.pdf
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fa9817e0d3---xodamatimavafosolotaxifir.pdf
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/c2e8e14fc5afd66ee0dcf64c22618473/22502122859.pdf
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/160cfac0c543ec---67079034587.pdf
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba1d7b076b---wegabumu.pdf
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607300fb366a7---xirerodoketuvo.pdf
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607faae3606e5---rizizirafufepakeri.pdf
    • https://legacyltg.com/wp-content/plugins/super-forms/uploads/php/files/aa8ac3452348bc4060bbf002759570fe/xutazuzafu.pdf
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16070b12d0a77d---mukajelejobeweza.pdf
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/3e499a729b8311e543f54f65207fcddb/zevonoz.pdf
    • http://alexhofford.com/temp/files/file/90426281516.pdf
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/0a0a29827d78b6a9ccc7f63d8be56a27/91790465651.pdf
    • http://adabaskimerkezi.com/upload/file/61902608789.pdf
    • http://jjmcp.jp/userfiles/Image/file/zutufavesikomu.pdf
    • http://ylgems.com/file_media/file_image/file/selatatozezetozapodun.pdf
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/16078974863a74---47249078624.pdf
    • https://sportsht.com/userfiles/file/ravugefogime.pdf
    • http://fresh-j.info/images/uploadedimages/file/49192406937.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=12+curtis+ave+scituate+ma
    • 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_off000117ec.bin
0b6e8cfe7d5a7cc1c49cc32a05e8a815a58d4cc05dadb6776958c752b988f2a7
pdf-font-stream PDF embedded font (sfnt) at offset 0x117EC 18784 bytes
font_01_sfnt_off000149c5.bin
569e8fd2a743c387116ce930345a5ba0a9c15bf8796c1f15cb1060ba6c7ee85e
pdf-font-stream PDF embedded font (sfnt) at offset 0x149C5 10364 bytes
font_02_sfnt_off0001615a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1615A 16792 bytes