Malicious PDF — malware analysis report

Static analysis result for SHA-256 4860d66dd900cf93…

MALICIOUS

PDF

87.1 KB Created: 2021-08-08 21:48:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a1a93a3f91bc3324864f5b15a1a356a3 SHA-1: 83915d4625836767436ff48737ff0c62f04f2fac SHA-256: 4860d66dd900cf9356c5a7d85d9c679811e94574bfd5a061d7dbb0fd43cc3a26
96 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to various domains, many of which appear to be compromised or disposable hosting. The ML classifier strongly indicates maliciousness, and the structure suggests an attempt to manipulate search engine results or redirect users to malicious content. No scripts were extracted, but the presence of multiple external links and the ML detection point to a malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 5

  • 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://gyandeepjkss.org/userfiles/file/98989136274.pdf
    • http://zpb-maciejewski.pl/upload/fck/file/dezesi.pdf
    • https://aedwea.com/upload/foto/21725162816.pdf
    • http://birzebbugastpetersfc.com/files/file/31643461155.pdf
    • http://fmafirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/26293386237.pdf
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/f58c186727d0d0e7ab3c357c5c4006f0/jegurejuluzigonuzali.pdf
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/ba6tb05ql5cbgolm387cj7ija4/76554800436.pdf
    • http://hoteldanang.vn/uploads/images/files/silutufujidatuve.pdf
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/85fa0bd147e50ab8e475c921d302a321/foxabopisozidoke.pdf
    • http://indianspringhomes.net/userfiles/files/pisegomoxovar.pdf
    • https://progin.ch/ckfinder/userfiles/files/36607399972.pdf
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16090c2ef13fdd---mukirezefuva.pdf
    • http://szao-spb.ru/images/news/file/didusolokiruve.pdf
    • http://birnagarcollege.in/userfiles/file/xovixutotibojerepu.pdf
    • https://beaszemin.com/files/gizesaxoxolu.pdf
    • http://andrewsexes.org/clients/867461/File/vufitire.pdf
    • http://alibabashipping.com/userfiles/file/32726110056.pdf
    • https://www.synergyheart2heart.team/wp-content/plugins/super-forms/uploads/php/files/750uknpl832ofg8qtnd8bjllr0/89126638189.pdf
    • https://ankaratemizlikcim.com/depo/sayfaresim/file/82016857018.pdf
    • https://ip-pharma.net/data/files/91771818197.pdf
    • http://gimnazjum-krasiczyn.pl/img/userfiles/file/jibinorokawiwisi.pdf
    • https://cincia.ro/ckfinder/userfiles/files/ribalekolelilol.pdf
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609b770391b90---74466502955.pdf
    • http://lawrence-spruill.com/clients/42275/File/lugeforozog.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=bank+customer+satisfaction+survey+questions+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_off0000f020.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF020 16792 bytes
font_01_sfnt_off00010832.bin
bb20496f2b20a50ba2ab07e3a0a73220f04d08a70da06694bbb85744c797d0bf
pdf-font-stream PDF embedded font (sfnt) at offset 0x10832 16948 bytes
font_02_sfnt_off000134af.bin
53b5d2dde53a60ecc9def83f142b04e7895e6fbacacbaa668018285ca93d55cc
pdf-font-stream PDF embedded font (sfnt) at offset 0x134AF 11304 bytes