Malicious PDF — malware analysis report

Static analysis result for SHA-256 943b57ba5839196c…

MALICIOUS

PDF

86.3 KB Created: 2021-09-16 21:34:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7bce3ffb0040ed4db41888d4830c3962 SHA-1: 9f68316710b689e4414d06c88bea207a45b38a64 SHA-256: 943b57ba5839196c9376898916d9ff7ed63bcdd71d2976c02bd8cd4aaf44922e
184 Risk Score

Malware Insights

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

The sample is a PDF containing embedded JavaScript and a large number of external URIs, many of which point to compromised CMS uploads or disposable hosting. ClamAV detected this as Pdf.Phishing.Trojan, and ML classifiers also flagged it as malicious. The embedded JavaScript and link farm structure strongly suggest the document is intended to exploit vulnerabilities or trick the user into downloading a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://pistant.ru/uplcv?utm_term=android+phone+storage+full+but+it%27s+not PDF link annotation
    • http://westhollywood.ilovepokebar.com/uploads/files/pitoxi.pdfIn PDF document text
    • http://euhoca.com/js/ckfinder/userfiles/files/rivujelemebivirudaza.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/b477b0bf4020e5ff68d2c78374334141/ketukoratoraxuvekudow.pdfIn PDF document text
    • http://montpellier-business-plan.fr/mbp/upload/images/images/upload/ckfinder/leridalutubimalipene.pdfIn PDF document text
    • http://hiredriver.com/uploads/assets/files/91750806932.pdfIn PDF document text
    • https://www.spitalmoldovanoua.ro/ckfinder/userfiles/files/difiwo.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/675ade1b61c295f934334aaf4b5e035e/wigakipijoxulexixix.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16138fa40390e0---bativuwisoworuka.pdfIn PDF document text
    • http://dietaltop.com/userfiles/files/3227405460.pdfIn PDF document text
    • http://fratellibeninca.com/images/file/ratenolutogegijirifug.pdfIn PDF document text
    • http://www.naturhalles.fr/fckeditor/userfiles/file/jifukeramapu.pdfIn PDF document text
    • https://faresaldabbous.com/uploads/file/jazabaluxixamedos.pdfIn PDF document text
    • http://fsnmmaterials.com/UPFILE/userfiles/files/47673352245.pdfIn PDF document text
    • https://qpshouse.com/upload/image/file/46351313170.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613e5cc354b79---99297517175.pdfIn PDF document text
    • http://jacsonsfurniture.com/userfiles/file/vutefapixumosemod.pdfIn PDF document text
    • https://pepsima.biz/files/file/bumigi.pdfIn PDF document text
    • http://ventensis.lt/public/ckfinder/userfiles/files/ximodetowasogeweda.pdfIn PDF document text
    • http://nhatrangpalacehotel.com/app/webroot/upload/files/joxiwamuderuva.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb1d4ac421---tatexudizura.pdfIn PDF document text
    • https://travellifeafrica.com/ci/userfiles/files/16871232043.pdfIn PDF document text
    • https://cape-electronics.com/media/file/felupibafawivaki.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/161304370d76dc---27251688303.pdfIn PDF document text
    • http://studiogiamberardino.it/userfiles/files/68268143162.pdfIn PDF document text
    • http://140.121.161.111/ckfinder/userfiles/files/4656404714.pdfPDF link annotation
    • http://a-swiss.com/upload/userfiles/file/51535681663.pdfIn PDF document text
    • http://xn--80aafjbawrcdgsodbdciig4a5v.xn--p1ai/pict/file/zujafozavakewamuvepenigo.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_off0000ebbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBBD 17916 bytes
SHA-256: 669e8345600d1fbd423f60602afa639cfee7a7aba6c60a9801ec90b506314ec6
font_01_sfnt_off00011a2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A2B 11032 bytes
SHA-256: c1593877da195d633e15f43b0c5aa0edccc114440b7d362e6a322fd7105088ef
font_02_sfnt_off00013365.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13365 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1