Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5ebf7df50acbd35…

MALICIOUS

PDF

78.7 KB Created: 2021-09-12 19:01:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: dd1f7a547f4f8a16bb88a022fa95fc3d SHA-1: 0adb1136d15acb54696870421e723f0292d364cc SHA-256: d5ebf7df50acbd35642dceadd3d40f732ef247ace10a648a8ca9f957e529c8ad
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The presence of numerous PDF links on disposable hosting further supports a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 6

  • 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.
  • 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://synerhu.ru/uplcv?utm_term=pure+physics+book+pdf PDF link annotation
    • http://memsports.com.br/admin/libs/ckeditor/ckfinder/files/bikedujiwefevimodivapuba.pdfIn PDF document text
    • https://inprovitperu.com/ckfinder/userfiles/files/baxifiv.pdfIn PDF document text
    • http://shukokai-voves.fr/userfiles/file/74426167689.pdfIn PDF document text
    • https://e-uchebnici.com/img/file/rajibofen.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee32abd803---43950759515.pdfIn PDF document text
    • http://biolabsrl.org/userfiles/files/4332902599.pdfIn PDF document text
    • http://hichipper.com/hichipper/uploadfile/file/2021090308075173499.pdfIn PDF document text
    • https://ssvacancy.com/ckfinder/userfiles/files/30622229566.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/ac0c8a55c294143c55b8d7ccca80aa5f/5922747192.pdfIn PDF document text
    • http://mtt-association.fr/upload/file/2598401050.pdfIn PDF document text
    • https://macroedunet.com/userfiles/file/64200531614.pdfIn PDF document text
    • https://netshopnepal.com/userfiles/file/24683344151.pdfIn PDF document text
    • http://timnhanhonline.vn/upload/files/3828329623.pdfIn PDF document text
    • http://www.leposeur.fr/site/upload/ckfinder/files/24769081396.pdfIn PDF document text
    • https://turkeyinsurance.info/images/file/73700990049.pdfIn PDF document text
    • http://babijie.com/upload_fck/file/2021-9-10/20210910163633591142.pdfIn PDF document text
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/c0a14616c190a87e79b9d527906df288/pukositabigi.pdfIn PDF document text
    • https://lompatjauh.com/contents/files/77014133469.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/4tbt71md3redvt4dvsfa0cbpph/80627739844.pdfIn PDF document text
    • http://umartravel.com/files/kifufevedodozekevexukole.pdfIn PDF document text
    • https://metrosecuritynepal.com/assets/userfiles/files/9251800631.pdfIn PDF document text
    • http://d2dgroup.net/upload/files/rizobunakopidopoxo.pdfIn PDF document text
    • http://csc0731.com/userfiles/file/20210910070353_c2iy2g.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_off0000d180.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD180 16828 bytes
SHA-256: aa4d652a9498e97db6e7ee6b9cc4259c74d4e4033a9f5653047a41a0dab678df
font_01_sfnt_off0000fce6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCE6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000114fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114FD 10752 bytes
SHA-256: 06607021f847230141aa970f4122a4ab78e2463ef861cf93ceda253372dce171