Malicious PDF — malware analysis report

Static analysis result for SHA-256 39dc37916946c2ab…

MALICIOUS

PDF

71.5 KB Created: 2021-09-16 19:46:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ff0878e9395c493934e63500464568dc SHA-1: 9d86fd0bd1a39a260c2b7758dade3e4dc677aec7 SHA-256: 39dc37916946c2aba9b9fd6db46bccb6ada9496dfd0ce1403248796a6cd92161
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URI heuristics point towards the use of embedded JavaScript to facilitate these redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://inwebjor.ru/uplcv?utm_term=how+to+connect+bluetooth+from+phone+to+tv PDF link annotation
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139cd4b9a54d---56633393429.pdfIn PDF document text
    • http://loca-granderoue-montaletang.com/ckfinder/userfiles/files/pobirakuzodeganuvu.pdfIn PDF document text
    • https://nepalmicrofinancesummit.org/userfiles/files/tibovusawogo.pdfIn PDF document text
    • https://jmbarrenetxea.soinuenea.eus/files/galeria/files/wogopiwofizijafakexejizik.pdfIn PDF document text
    • http://ltptech.vn/uploads/userfiles/file/24416411882.pdfIn PDF document text
    • http://hawaiisushi.iorderfoods.com/uploads/files/68703292633.pdfIn PDF document text
    • https://fotobolfestmeny.hu/mvc/userfiles/file/12066317250.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/e29fc3e50a5413f8d090535e5128faac/zitodovezix.pdfIn PDF document text
    • http://nilesk.com/userfiles/file/73639202790.pdfIn PDF document text
    • https://valserve.in/web/k/main_admin/ckfinder/userfiles/files/71916735653.pdfIn PDF document text
    • http://mydreamtuscanwedding.com/editor_up/refepidusujesawimub.pdfIn PDF document text
    • http://185.33.116.145/~acus01/upload/files/fapivasadivitosapitetepin.pdfPDF link annotation
    • https://jungleflightchiangmai.com/Uploads/files/xowolafopitesexobemin.pdfIn PDF document text
    • http://gd-weimi.com/upfolder/e/files/20210903141412.pdfIn PDF document text
    • http://abakus-routing.co.uk/ckfinder/userfiles/files/34875311018.pdfIn PDF document text
    • https://dpengineers.info/admin/userfiles/file/54464739017.pdfIn PDF document text
    • http://detskypohar.cz/upload/file/76221885237.pdfIn PDF document text
    • https://mccartha-cobb.com/userfiles/files/gesakojesukuwufav.pdfIn PDF document text
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/6730e8f5f896fa23d82431e7b0bcfbe7/31676804347.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/161333fb864578---kikimi.pdfIn PDF document text
    • https://edinburghpools.com/contents/files/3121899589.pdfIn PDF document text
    • https://snapstudios.ca/userfiles/file/22059778924.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614251c6e157b---63533207283.pdfIn PDF document text
    • http://hmed.vn/upload/files/pitafoxoretuduripesomu.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1613c9e52d998c---59332453793.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_off0000b942.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB942 15228 bytes
SHA-256: 2f9bf744a05f3cc3cecf65200a1f490554f57c4ca3968ab920b2d2c34d5e2df2
font_01_sfnt_off0000df79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF79 10708 bytes
SHA-256: 55e26753ad9831a16d97d7d11a0f47c0c2d25e65eee4414969366939e32a4070
font_02_sfnt_off0000f7a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7A4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1