Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a1fe9efb593033d…

MALICIOUS

PDF

81.5 KB Created: 2021-09-18 08:07:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7e254324474567fa1fc5293aea46562b SHA-1: 246478158b2b21573bbd12a586079f5761a1098f SHA-256: 9a1fe9efb593033d4ab3e35494420e0805fe91f080bac18b95aeb1b22843abdf
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content. It also features a link farm pointing to numerous external URLs, many hosted on compromised WordPress sites or disposable domains, suggesting an attempt to obscure the ultimate destination or distribute payloads. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://ketchas.ru/uplcv?utm_term=wonder+book+read+online PDF link annotation
    • https://baobiachau.com/luutru/files/55560306873.pdfIn PDF document text
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/4fa6d079e91dca4777a2a85fab4ffa8c/kutasavizapezija.pdfIn PDF document text
    • https://kaptenhoki.com/contents/files/3450482548.pdfIn PDF document text
    • https://pernambucoimortal.com/imagens/files/58671246711.pdfIn PDF document text
    • https://freebcard.com/ckfinder/userfiles/files/4399887950.pdfIn PDF document text
    • http://majorpropertygroup.com/userfiles/files/tufisenubasirenuzuled.pdfIn PDF document text
    • https://nucamsa.es/userfiles/files/liwanegomexitumenitolijo.pdfIn PDF document text
    • https://ijp2.com/contents/files/74818806537.pdfIn PDF document text
    • http://blow-w124.com/js/upload/files/pewokuwatetujusajajubid.pdfIn PDF document text
    • http://havefuntogether.com/image/upload/File/55116909940.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/f3a3c68b7553538f50236ba81dda6e8f/18184976219.pdfIn PDF document text
    • https://medpressa.ru/files/file/rinekerab.pdfIn PDF document text
    • https://aczv.fr/userfiles/file/nusul.pdfIn PDF document text
    • http://manvilastrust-org.bvirani.com/ckfinder/userfiles/files/7967482146.pdfIn PDF document text
    • http://loadcell.vn/Images_upload/files/muliwisosej.pdfIn PDF document text
    • http://www.biharikft.hu/bihari-admin/ckfinder/userfiles/files/xawikus.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/161434abc6c65e---nuvega.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613bb2be30719---31546768984.pdfIn PDF document text
    • http://e-motyle.natura2000.pl/imgturysta/files/jisox.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142a39868770---89238738142.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16140618de903e---34173517075.pdfIn PDF document text
    • https://lerong.vn/wp-content/plugins/super-forms/uploads/php/files/4db0ef5bf6aa400d419a5dbd5b1ac8f5/67627796612.pdfIn PDF document text
    • http://tuecpa.com/file_media/file_image/file/92979566645.pdfIn PDF document text
    • http://medeeatour.ro/mm/file/67226184004.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_off0000dc26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC26 10200 bytes
SHA-256: e1c1a3847c8352d5c06a65f5611109a8f360005ee1a0a5541dcd4c45d81cff96
font_01_sfnt_off0000f309.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF309 17480 bytes
SHA-256: 4bf1400fa5c60b763ab1664766c4c2175112cdcc0cd29f6adf5f54324077600e
font_02_sfnt_off00012058.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12058 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1