Malicious PDF — malware analysis report

Static analysis result for SHA-256 831bb6dd25430ba7…

MALICIOUS

PDF

86.1 KB Created: 2021-09-04 06:37:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: e589c51e952f29c6d2a12dcf40c82aaa SHA-1: 8152f97c3075ec2f9f3d471c5256307ce2491e64 SHA-256: 831bb6dd25430ba7834bf706b64996896ae664861ca7affa9cc2422c7e4b515d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://nomylo.ru/uplcv?utm_term=lobsang+rampa+pdf+books PDF link annotation
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c555579b1f7---rovipitulofojozo.pdfIn PDF document text
    • https://edarky.net/data/file/nelutaloxinokewupok.pdfIn PDF document text
    • http://biosurfest.com/userfiles/files/fazusubefetomadedotuvewal.pdfIn PDF document text
    • http://status-go.net/gfx/userfiles/files/mukodibukipipetatutilaxa.pdfIn PDF document text
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/tn4phdv25ad5aeivit41lgi02c/debupubinoxid.pdfIn PDF document text
    • https://a-pointpro.com/cms/ckfinder/userfiles/files/mebifixazilutikinipobojo.pdfIn PDF document text
    • http://notar-frings.de/userfiles/file/dawoxubonavopum.pdfIn PDF document text
    • http://afgventuregroup.com/cfiles/file/61045983054.pdfIn PDF document text
    • http://kaizousha.com/js/upload/files/11499557870.pdfIn PDF document text
    • http://dgjst.com/upfile/file/62452022429.pdfIn PDF document text
    • http://2440027.ru/upload/file/52208550764.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a7cd08c86d2---wemerozibupob.pdfIn PDF document text
    • http://euroear.eu/ckfinder/userfiles/files/21192302694.pdfIn PDF document text
    • https://esportenerd.com/app/webroot/ckfinder/userfiles/files/39513040664.pdfIn PDF document text
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a4db315a800---76697753801.pdfIn PDF document text
    • https://ahreco.com/uploads/news_file/xewinamibutapa.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bd949cfcd3---38640733439.pdfIn PDF document text
    • http://futurepoolandspa.com/ckfinder/userfiles/files/fuveziwofaxe.pdfIn PDF document text
    • https://poganyvolgyi.hu/userfiles/file/84572968425.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/81ab8225e12defa1d3b58bfb34151112/fudifazoj.pdfIn PDF document text
    • http://ambartakip.net/belgeler/file/senigisunan.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8c3a9c08c1---16548263862.pdfIn PDF document text
    • http://csc0512.com/userfiles/file/20210615181503_38lhv4.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_off0000ead0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000102e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102E7 10660 bytes
SHA-256: 9ad5e843729b4e4342732461f07d80aa76caa9b4935e16b86998e4bde2293e50
font_02_sfnt_off00011ada.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ADA 18416 bytes
SHA-256: e6940c727667277d9836e0baccc4896063e28def7fc9dccc2f19cfad8131120d