Malicious PDF — malware analysis report

Static analysis result for SHA-256 835caa422106bf52…

MALICIOUS

PDF

89.2 KB Created: 2021-06-29 06:18:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f07f74dd5d64ea43cec78d623ce0113b SHA-1: 777781b080853ebdec3712c6d6f303a60258d08a SHA-256: 835caa422106bf52d588ca04029a52a748e730ab92d48954c440fc7fdb06b4d8
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised WordPress sites, suggesting an attempt to redirect users to malicious content. The presence of external URIs and link farm heuristics strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c9a808915ef---tixeboronalijoxure.pdf
    • http://freeski.hu/freeski/file/nizofawunuwezelalusixet.pdf
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/246419eb7255d0d86b5fca746257eb05/xusasobanak.pdf
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a8dcde66e0d---monasipuxamefovasolil.pdf
    • http://zge-led.com/luodan/images/userfiles/file/2619616480.pdf
    • https://sealordhotels.com/ckfinder/userfiles/files/66563234437.pdf
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/160da4594a2126---lunobufireloxonuwola.pdf
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071e46095691---xakofu.pdf
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/991a51448560b9ba6d896581cd54da5d/21902210196.pdf
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608df411683c3---6656759599.pdf
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160b336580275b---3557173932.pdf
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/fe9e237c13870afb2d745e27778c794d/wukabowajesisebizozo.pdf
    • http://archi1919.com/smlclub-files/file/besumisetaxugojusaloxuv.pdf
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609bfca9ce0a7---budewuxabubakibezol.pdf
    • http://barbusci.it/maisUserFile/file/68409977031.pdf
    • http://photou.cc//ckfinder/userfiles/files/18123750238.pdf
    • http://theettiaresottawa.ca/clients/e/e8/e8f54e69a7463df9fd0adff13cd8e90f/File/degidevuwoxododulufosovaf.pdf
    • https://systematix.pl/userfiles/file/83448167041.pdf
    • http://laweasy.kr/userfiles/file/82869819437.pdf
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160732a1f0ae08---zagumejemunaludeveme.pdf
    • http://namngonviet.com/user-/files/potemaxexanusededipug.pdf
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/0a86c5d92d2d84c2cf11a1ed84ff5df1/sosudupexupivef.pdf
    • http://goergenpainting.com/clients/0/0d/0d1038892961fdbf96b6a8e7e8daca8f/File/58758732535.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=hack+creative+destruction+android
    • 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_off0000f9e3.bin
cf71a7e39308eed4a89638eafdcdd8d8e31984117d5df3c84b3e24a59274f4ea
pdf-font-stream PDF embedded font (sfnt) at offset 0xF9E3 16800 bytes
font_01_sfnt_off000125d0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x125D0 16792 bytes
font_02_sfnt_off00013de7.bin
d87dbc203a8b7eabfb18e12f0ebc2de2139260afa2aa11bdcb8305f297c6e490
pdf-font-stream PDF embedded font (sfnt) at offset 0x13DE7 10568 bytes