Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd523fc7e57d8190…

MALICIOUS

PDF

86.5 KB Created: 2021-07-03 22:49:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d5491a4b7e952220f25c9db20e0373a5 SHA-1: 84be791ff8165f88370002332ce6d18c0a0b23d5 SHA-256: bd523fc7e57d8190dda8dd1bdd70e563f65fc53806c930bd491b379df773f21e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards a malicious document, potentially leveraging embedded JavaScript for exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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 https://irlanc.ru/uplcv?utm_term=arithmetic+sequence+find+n
    • http://absolutelyneon.com/userfiles/file/kozuji.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/9rui1mmsj4mf679nbak7olqrj7/14184208469.pdf
    • https://bczenekar.hu/files/file/napulasibarupovepo.pdf
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/bf4293555f66ead02b10a7ec0baf73d4/mopivadigufefamemo.pdf
    • http://klasykarozrywki.pl/public/images/fck/file/90015656621.pdf
    • http://novussiteyonetimi.com/uploads/file/55710009720.pdf
    • http://kubak-ubezpieczenia.pl/userfiles/file/lixelugiv.pdf
    • http://movementlab.dk/userfiles/file/75763730100.pdf
    • http://currycornersugarland.com/admin/images/file/runepixisozavupi.pdf
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160d9231ed7ed1---95878628181.pdf
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/160806be86a06d---4158346427.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c5318b3a52---xezolepakaxekovubewabun.pdf
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/qohfl9lgnkdcbm9hdrap350s0b/47094881701.pdf
    • https://www.northernillumination.com/wp-content/plugins/super-forms/uploads/php/files/43c68a66c5b16393578601f69fed02e4/mofakidepob.pdf
    • https://pilotcenter.gr/wp-content/plugins/super-forms/uploads/php/files/kosc55nfucba1bcri7m37p96fs/35480124026.pdf
    • http://kxnjl.com/userfiles/files/mamerage.pdf
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160723494a9155---zuwirero.pdf
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/54522555219.pdf
    • http://swaminarayangm.org/userfiles/file/gonitu.pdf
    • http://jkbprivateiti.com/userfiles/file/jabosewesogewip.pdf
    • http://massintech.ru/img/outer/files/36612721769.pdf
    • https://amitadevnani.com/userfiles/file/27404353456.pdf
    • http://danies.ru/ckfinder/userfiles/files/43104422653.pdf
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608456fee76d0---49905938019.pdf
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/73epvs81fusmc2g2dq03m9iskf/lujexu.pdf
    • http://avtoarka.ru/wp-content/plugins/super-forms/uploads/php/files/747ccca285c75d4db7e02cdc9037e898/32035994556.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_off0000ed66.bin
f12ff84422addc41ee529de13c9fe94fa3a0eb33e66d308f3131c12988ae4040
pdf-font-stream PDF embedded font (sfnt) at offset 0xED66 10640 bytes
font_01_sfnt_off00010562.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10562 16792 bytes
font_02_sfnt_off00011d74.bin
6e050b05f7674c1030517eba5817a224f80b2e0f9d2746eef961d374fb871664
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D74 17792 bytes