Malicious PDF — malware analysis report

Static analysis result for SHA-256 990f48e86981f54f…

MALICIOUS

PDF

87.8 KB Created: 2021-06-26 08:51:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 24112f107c9b32e8516262cfcf1c94d1 SHA-1: 4d629a69478ebcc315beb14488a09051d9a4b336 SHA-256: 990f48e86981f54f1367c2efde7ebe3c2f6e1180d1ae81892a57b0f0d4f330da
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed for SEO poisoning or phishing. The ML classifier and ClamAV detection strongly suggest malicious intent, with the primary goal being to redirect users to potentially harmful content. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • 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.
  • 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://queure.ru/uplcv?utm_term=topics+in+algebra+and+analysis+pdf
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/4ns5o1u6vmr2dbpf3klk9egd9d/dozazevozisakow.pdf
    • http://www.redactordecontenidos.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16094653a03812---6487779393.pdf
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/4r9ltg65147uhpllunjm6edvu0/jimudexiru.pdf
    • https://hotelristorantenovecento.it/wp-content/plugins/super-forms/uploads/php/files/4f7055912637d38a39b38f395d3e4a6d/64586849996.pdf
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607151e6a3599---49457967841.pdf
    • https://hoangnhataudio.vn/media/files/4020464349.pdf
    • http://www.tobywells.org/media/fckdir/file/21440886801.pdf
    • http://szentdorottyapatika.hu/files/89060207652.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/0b2e2f453f631faeaaab43d7d288e3eb/44155266408.pdf
    • http://fotografoenricogiampieri.it/userfiles/files/77671384073.pdf
    • https://sonarmusic.hu/up_image/file/vezafusazovizusaxon.pdf
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160c1e5941b733---somotuje.pdf
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16095b7ce598ea---xexis.pdf
    • http://idroter.org/userfiles/files/67682830545.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/9f49965e2159e7bc5b5f35d471305493/dodukivinepamoloveda.pdf
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/e40be2edec84343ad454a86e0a04d8bb/5387662289.pdf
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/6f81febfebbd371bb506531ec1c7f581/94431153651.pdf
    • http://fixmyhelicopter.com/project-new/christianbook/upload_images/file/pabisawejulogufuva.pdf
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/b55ec59552f828a63000d3ddda878e72/14114099648.pdf
    • http://dzbnf.com/upload/file///dovuxep.pdf
    • http://aivieksteslaivas.lv/userfiles/file/10434227871.pdf
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16089798a25e1d---latunabunelibi.pdf
    • http://drstevealbrecht.com/wp-content/plugins/super-forms/uploads/php/files/b122a6e0f7174d507f8abe1467f795ff/zuwiresevowulilafegezud.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160cc692493a94---40596248818.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_off0000f428.bin
64aa43db5c40fdf7e5cd8a06f3b3658651490c1406ac3e11148df0a17e799de8
pdf-font-stream PDF embedded font (sfnt) at offset 0xF428 17460 bytes
font_01_sfnt_off0001209f.bin
c2c43515a0f492fa1b29164513b28605357722f93978b2cf665e07cccdd07882
pdf-font-stream PDF embedded font (sfnt) at offset 0x1209F 10916 bytes
font_02_sfnt_off0001399b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1399B 16792 bytes