Malicious PDF — malware analysis report

Static analysis result for SHA-256 a53cd1557de36c74…

MALICIOUS

PDF

83.8 KB Created: 2021-09-07 16:28:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: cc42707055c9ae911bb0cd964dfe812e SHA-1: fdf160f77c4ca8991d91b4562f357be084ab6805 SHA-256: a53cd1557de36c74cbb37b299b6de215aa9e9891ebfbeebd7c13c9cff11ee337
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains multiple heuristics indicating it is a link farm pointing to potentially compromised WordPress sites and raw IP addresses, suggesting an attempt to distribute malicious files. The presence of a 'download button' heuristic further supports the lure-based attack pattern. ClamAV detection and ML classification confirm the malicious nature of the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 8

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/ba4058981b281cf0faf2308314a5b4b0/146601892.pdf In PDF document text
    • http://myarrahnu.com/mo_images/files/pijov.pdfIn PDF document text
    • http://hyundaihungthinh.com/uploads/images/files/65709998534.pdfIn PDF document text
    • https://piauiaqui.com/ckfinder/files/73249019316.pdfIn PDF document text
    • http://rittenhousereunion.com/clients/a/ad/ad7d26974070b67854a29702aed78614/File/japajavukevop.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/e44f7522d7e0f8006947a438250d2cfd/xasamimerevujozenev.pdfIn PDF document text
    • http://imailbox.nl/images/uploadedimages/file/foxovorusaxidebegugomuju.pdfIn PDF document text
    • http://dioblina.eu/userfiles/file/67734343911.pdfIn PDF document text
    • http://pogservice.ru/userfiles/file/notisanimezig.pdfIn PDF document text
    • https://affordans.com/ckfinder/userfiles/files/voxifugodi.pdfIn PDF document text
    • http://keralabiblesociety.com/fck_uploads/file/41170521131.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/f6b1b7110e79843428000f81e926a426/jusalowuv.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/iti0rie5ji3dnkf4h7b9i48jdr/47735346651.pdfIn PDF document text
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/ptssvdk4r6ovktf00vjuhu4ua7/zovudes.pdfIn PDF document text
    • https://lacaune.hu/userfiles/file/siladamazinofun.pdfIn PDF document text
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/4q493tl5b23519h5psoinradpm/zujepuketodufudidasij.pdfIn PDF document text
    • http://140.121.125.49/ckfinder/userfiles/files/20210813_062849.pdfPDF link annotation
    • http://driver-jazda.pl/upload/file/bobanegosegewa.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606c861732dbd---60310078576.pdfIn PDF document text
    • http://aodaiminhhanh.com/app/webroot/uploads/files/98335661848.pdfIn PDF document text
    • http://babywagen24.de/userfiles/file/89372720381.pdfIn PDF document text
    • http://newmob.it/userfiles/files/95438775876.pdfIn PDF document text
    • http://allivecoat.com/userData/board/file/96531284328.pdfIn PDF document text
    • https://angkoronetour.com/userfiles/file/74763433985.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160873bb1d3902---luxeke.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=english+articles+worksheet+for+grade+6PDF link annotation
    • 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_off0000e01a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE01A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f831.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF831 11084 bytes
SHA-256: 219e5f3a99e93e3e1250031a2afe0c427104a25a4ec3939f14eece3d6776cede
font_02_sfnt_off000111de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111DE 18664 bytes
SHA-256: f57d89cecf19dec675d313f4ca9c672e9b84ade9141f55b0c2e1b0eb7a3f42cd