Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d8520d7b881d4f6…

MALICIOUS

PDF

75.2 KB Created: 2021-09-20 02:06:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 1c3b6e971c1eca0261a3df0d115d214f SHA-1: 96a6a5631a74a24aef6a80821a0d1777d29f366b SHA-256: 3d8520d7b881d4f60620d6873d330bf8fb5a3577467acf390fe25b96f4c3005c
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs that point to various websites. Several of these URLs lead to compromised CMS upload storage, indicating a potential phishing or malware distribution vector. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://xyoaa.org/sites/default/files/files/mologor.pdf In PDF document text
    • http://stefanourso.com/public/userfiles/file/64371833918.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/161408d892f231---japiwupasusadetedurosi.pdfIn PDF document text
    • http://kiemdinhcan.com/Images_upload/files/30738702355.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161306574a991d---raxereroxosonufute.pdfIn PDF document text
    • http://anipetkingdom.com/webroot/img/files/feder.pdfIn PDF document text
    • http://keacg.com/upload/files/49242773538.pdfIn PDF document text
    • http://braciszewska-klimek.pl/fck_files/file/23924869847.pdfIn PDF document text
    • https://thefertilizergranulator.com/d/files/95216306857.pdfIn PDF document text
    • http://thenikharvconsultancy.com/userfiles/file/9029827328.pdfIn PDF document text
    • http://elsped.hu/files/file/furalelarovomuvunim.pdfIn PDF document text
    • http://www.bluewhaleline.com/image/upload/File/wusevemavavofidafepiwuso.pdfIn PDF document text
    • http://esangsok.com/upfile/files/pexosemosumijipisijen.pdfIn PDF document text
    • http://sahrugs.com/userfiles/file/28588847629.pdfIn PDF document text
    • https://k-barrierfree.com/FileData/ckfinder/files/20210916_B0C27A30CF0F8883.pdfIn PDF document text
    • http://koopmankennedyfeller.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/boxevalefugo.pdfIn PDF document text
    • http://voyagevietnamlaos.com/hinhanh/file/kafowapanaj.pdfIn PDF document text
    • http://kirilmazbardak.com/userfiles/file/69015043152.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/89d4f2adb55a5415cccb639d928acb9a/61716604785.pdfIn PDF document text
    • https://italvaping.com/file/48387021809.pdfIn PDF document text
    • http://carbonelite.ru/file/79122476779.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=watch+my+hero+academia+for+free+onlinePDF 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_off0000c34d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC34D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB64 10680 bytes
SHA-256: cfda29023c22b67469629c0ddddc64e0ff528f3b5fac32c317b06e3b8ad4c10f
font_02_sfnt_off0000f3b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3B6 16824 bytes
SHA-256: c0db9b9ddaff613d50e527f87c058612500f45aafb7581c848369202944e0413