Malicious PDF — malware analysis report

Static analysis result for SHA-256 13a4e2511f01c6f2…

MALICIOUS

PDF

86.7 KB Created: 2021-07-20 03:23:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ec731a39f1655a771595c5d3f4061e43 SHA-1: 50026b49e9cfd707aa56561b46cb538253131100 SHA-256: 13a4e2511f01c6f229f10dc3d441148a2d3366e58a6eaffd750d6f724a757ecc
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links. The embedded JavaScript may be used to further obfuscate the malicious links or initiate a download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/5a5d852bbdaf77686aeac5ff4232cc5d/vepekevorunamab.pdf
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ab48654b5a6---52378336985.pdf
    • http://d4sontario.org/clients/e/ed/ed023a0734c265ca673a92d1d81de675/File/60332891845.pdf
    • http://blesk-stroy.ru/userfiles/files/kesareziwowodaw.pdf
    • http://roanfamily.net/clients/0/01/01b24a6c100194bbc8678883f3cd4a53/File/42593595946.pdf
    • http://anhuizpyy.com/upload_fck/file/2021-5-6/20210506032910297319.pdf
    • http://classiccar-jp.com/js/upload/files/tositaluwudilikosatelo.pdf
    • http://blueyee.com/upload/file/161849261253.pdf
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd5e855d558---wobilemajowumerado.pdf
    • http://remproekt-m.ru/admin/ckfinder/userfiles/files/20638984810.pdf
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16098410ba0b6c---95641510029.pdf
    • http://rusiuojigalvoji.lt/wp-content/plugins/formcraft/file-upload/server/content/files/1607372e40b3e9---33983963469.pdf
    • http://mindentudor.hu/userfiles/file/77551280567.pdf
    • http://longarmquiltacademy.net/fckeditor/userfiles/file/82283064445.pdf
    • http://aucoindeshalles.com/menu/file/xiwelebezokiletake.pdf
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/c880f57abe32f30496c9cb4f02c310b7/51526448534.pdf
    • http://allaboutdowney.com/userimages/bupilizan.pdf
    • https://likeevent.it/writable/public/userfiles/file/silodixolijexekixig.pdf
    • https://www.gasserbush.com/wp-content/plugins/super-forms/uploads/php/files/ab88d9faf1eca2e0e566c1394baa0bb8/75375978004.pdf
    • http://bigdoughpizza.com/uploads/files/92739491819.pdf
    • https://best-label.com/upload/files/wutirifi.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=clinical+scientist+neurophysiology
    • 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_off0000ef0e.bin
b5e7f9cb99b08c817ca614e6ae4c74c25a48ca055345ecf5758c4c620ed1af27
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF0E 16848 bytes
font_01_sfnt_off00011ac7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11AC7 16792 bytes
font_02_sfnt_off000132de.bin
c78fd6eeb99bc3f633e08fed7174beb5c8494e4002df64668b3ad8237b46a00e
pdf-font-stream PDF embedded font (sfnt) at offset 0x132DE 10900 bytes