Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef70b1f3e53d6fc9…

MALICIOUS

PDF

113.6 KB Created: 2021-09-05 04:37:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: de42917eaa159454cd0a20aa9e1407d0 SHA-1: 4fecd1a4c3abd858657dd647fcf3f60bd73332b1 SHA-256: ef70b1f3e53d6fc9edac0445717a2bbee264df22a1f62ba01736f39f6f9e5194
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The PDF structure and embedded URLs suggest an attempt to exploit user trust and deliver a malicious payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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 http://studiorinaldibedin.eu/userfiles/files/kowimevirewawukag.pdf In PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/47b4eb8fca4a0643891a0ec0bcc119b3/22429434961.pdfIn PDF document text
    • http://szalkasszorutacskok.hu/app/webroot/files/content/files/talusutowojip.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/otk1slr2p9ceh11n79gh01j40k/tuwufuxozivumurerofugo.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160746c77af841---42445041769.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160a86cc069dda---tuzikulug.pdfIn PDF document text
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8df4bae6c7---63120231473.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1609e6146b1440---varuwavepisomug.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c879e34c614---1450629880.pdfIn PDF document text
    • http://monkey-do.net/userfiles/file/kaxetafurajeda.pdfIn PDF document text
    • http://transbur.ru/admin/ckfinder/userfiles/files/momotajadefofapuxo.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/c2d79ef55f867c70f6211854afdeda73/sixapeparatameja.pdfIn PDF document text
    • http://leaders-adv.net/userfiles/file/wubofidosikom.pdfIn PDF document text
    • http://secretinvitation.net/images/files/95765769087.pdfIn PDF document text
    • http://diversecityuk.com/userfiles/file/wipewinitoj.pdfIn PDF document text
    • https://sedefartphotography.com/resimler/files/94326191360.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/um1p29asf3slmvdk305iplqghg/85147835131.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1607033cb320b9---58043333939.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/dc7b418eab1f8c288acf337e5e48f6c7/10627856982.pdfIn PDF document text
    • http://ndt-tl.ru/upload/file/37339291388.pdfIn PDF document text
    • https://reparationmobile.net/userfiles/file/28070061589.pdfIn PDF document text
    • http://appletechsolutions.com/userfiles/file/dogaluxawiku.pdfIn PDF document text
    • http://xn----7sbev0bhje.xn--p1ai/images/news/file/17991774042.pdfIn PDF document text
    • http://acm-medicali.it/userfiles/files/70794726944.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=ipcc+special+report+1.5+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001513f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1513F 20128 bytes
SHA-256: 2bae2911e3815e471e9c4a3010bb0bfa393f9890868dc56a7aefd11a7634124e
font_01_sfnt_off0001863b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1863B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00019e52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19E52 10712 bytes
SHA-256: 5c8b1b2a6b466b2c5303863d8d7bcc2d4a6daef49255dc8a42a9c494d1772d77