Malicious PDF — malware analysis report

Static analysis result for SHA-256 4789f058a4730adb…

MALICIOUS

PDF

82.2 KB Created: 2021-09-17 10:13:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 93948508b42bc32fdf514612d0c50fbd SHA-1: 31f2694a090eb5851b02399b74627770e9682ee4 SHA-256: 4789f058a4730adb6a745295c70591c57f99bbf61d09fd186284080880d48d52
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier, with multiple heuristics indicating it functions as a link farm. Several URLs point to compromised WordPress sites or disposable hosting, suggesting an attempt to lure users to malicious or phishing content. The PDF structure itself is indicative of a link farm rather than a legitimate document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://infrive.ru/uplcv?utm_term=lumia+640+xl+android PDF link annotation
    • http://cropscipublisher.com/files/upfiles/file/juboxusimudiwuso.pdfIn PDF document text
    • http://emanuelarombiarchitetto.eu/userfiles/files/64849089448.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/161434ddd0c923---bibaximifip.pdfIn PDF document text
    • https://activsport.ro/userfiles/file/likubefutivu.pdfIn PDF document text
    • http://www.520amis.com/upload/files/27977275014.pdfIn PDF document text
    • https://bizimpin.com/calisma2/files/uploads/lasiwuxurenozat.pdfIn PDF document text
    • http://domario.ru/userfiles/file/94260442360.pdfIn PDF document text
    • http://paillasse.hu/userfiles/file/92939012747.pdfIn PDF document text
    • https://tepatsasaran.com/contents/files/41838369320.pdfIn PDF document text
    • https://baptistfriends.org/media/porukutupodim.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/161431fb079754---70624639612.pdfIn PDF document text
    • http://2rent.gr/userfiles/file/tegomefaronukosesamiget.pdfIn PDF document text
    • http://thainightjob.com/ckfinder/userfiles/files/jakefefiwifesorotugiw.pdfIn PDF document text
    • http://abwlondonblvd.com/uploads/files/jupogetixexedatupo.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d99e2d0741---fonikakobogakukenuget.pdfIn PDF document text
    • https://total-sport.pl/img/upload/files/lokorenu.pdfIn PDF document text
    • https://yenicekentkaplicasi.com/userfiles/file/72720138302.pdfIn PDF document text
    • http://talentfuturesservices.com/sharpinstitute/images/files/30734119677.pdfIn PDF document text
    • http://bosch-elektronarzedzia.pl/catalog/file/fugidetesojezike.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/2b2c3188ee454c40def0005d4f4efbd5/48844845597.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613c51dee335a---wemixeronuvafakoduraxez.pdfIn PDF document text
    • https://samsungdvm.net/upload/ckfinder/files/xevipemogipelulisuv.pdfIn PDF document text
    • http://easyhypermarket.com/userfiles/file/gamirowimiko.pdfIn PDF document text
    • 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_off0000dc93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC93 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f4aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4AA 10540 bytes
SHA-256: 5876f8b48d97257bf8b6167d5ef52042d252dc451dbae93a6e08f082351897cd
font_02_sfnt_off00010c97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C97 17924 bytes
SHA-256: e5bc8e59d9170161be31d4590115c999d05e52ff2c13452c930abdade4a61591