Malicious PDF — malware analysis report

Static analysis result for SHA-256 5755a6434c03ee8c…

MALICIOUS

PDF

81.6 KB Created: 2021-09-12 22:18:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8a77b0a3a70d91eb58f979f2622c4fd0 SHA-1: c6de69a7acdea01d13af873d41f12db42625dd91 SHA-256: 5755a6434c03ee8c71a199605de0a5f007e299065c4ab5add51c35f90eed7dbd
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of multiple external URIs and link farm heuristics indicates an attempt to distribute or phish.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://almar-bus.pl/userfiles/file/businu.pdf In PDF document text
    • https://novsport.com/content/File/xegem.pdfIn PDF document text
    • https://khangle.vn/uploads/images/files/44471774519.pdfIn PDF document text
    • https://vetregistr.com/ckfinder/userfiles/files/93143941379.pdfIn PDF document text
    • http://mazraeir.com/images/upload/files/28440808798.pdfIn PDF document text
    • https://reclamesticker.nl/images/uploads/file/In PDF document text
    • http://remont-etalon.ru/upload/files/xosuwowawox.pdfIn PDF document text
    • http://bytip.net/filespath/files/20210902190714.pdfIn PDF document text
    • https://gaadalagi.com/contents/files/xemetemixilasod.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/71967247645.pdfIn PDF document text
    • http://nzozkrowodrza.pl/uploads/editor/file/pewowi.pdfIn PDF document text
    • https://padservhosting.com/userfiles/file/72834806794.pdfIn PDF document text
    • https://remini.hu/userfiles/file/babepuxabuwefis.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/d32cd360f3347bcf31e2f24ba500dc4a/fiwekafi.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613526f4c8f42---penabosexewebubusevuri.pdfIn PDF document text
    • https://grandhotelushba.com/userfiles/file/66971243054.pdfIn PDF document text
    • http://munnarinfo.in/userfiles/file/7705304441.pdfIn PDF document text
    • http://alexdisinfestazioni.com/userfiles/files/rozukakasaturileva.pdfIn PDF document text
    • http://terrietanaka.com/library/files/56761500453.pdfIn PDF document text
    • http://sinoorchids.com/image/file/xizoxuwele.pdfIn PDF document text
    • https://badoza.net/userfiles/file/43947420301.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/36490322494.pdfIn PDF document text
    • https://rougezenekar.hu/files/file/14510689970.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac4cb61212---puxijidefew.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=what+are+the+effects+of+deforestation+on+animalsPDF 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_off0000dbc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBC4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3DB 10732 bytes
SHA-256: 4812e3c14cdd8c3fb78ee781045359211dfb555bb920d03d791dce8dc1583ce8
font_02_sfnt_off00010c51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C51 16880 bytes
SHA-256: ccf3530df7a440dad931d9b0553e32d3d1627df17226d1221ccbda639306a518