Malicious PDF — malware analysis report

Static analysis result for SHA-256 66bc6081f6c08665…

MALICIOUS

PDF

142.6 KB Created: 2021-10-05 18:21:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 624921a8b1869a7b5b9bbf1663697502 SHA-1: f82b8bf34742741252942af1002c2fd6d95b93d8 SHA-256: 66bc6081f6c0866509de987c1346fcfc5231f2ff0faa19ad6b3e9d54264ae351
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to disposable domains, characteristic of a link farm used for phishing or distributing further malicious content. Although no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it is designed to exploit vulnerabilities or redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://pappteam.hu/userfiles/file/zaximun.pdf In PDF document text
    • http://liveisagenix.com/ckfinder/userfiles/files/femomavumi.pdfIn PDF document text
    • https://korovin.org/site/img_ufiles/12869549147.pdfIn PDF document text
    • http://gymostrov.eu/gymostrov/userfiles/file/21321628729.pdfIn PDF document text
    • https://callmarkinvestments.fortunekenya.com/callmark/files/6392700900.pdfIn PDF document text
    • http://letdentalab.com/img/files/85041195546.pdfIn PDF document text
    • http://ambulanceservice.pl/userfiles/file/xojawirefaxuvipexuj.pdfIn PDF document text
    • http://culfordequestriancentre.org/UserFiles/file/tevarexupepevaxiw.pdfIn PDF document text
    • http://186086.com/upload/files/jijuvotufepurifoxibexidi.pdfIn PDF document text
    • https://jeevadhara.org/work/london/userfiles/file/89374890840.pdfIn PDF document text
    • http://e-junghan.com/userData/board/file/sobej.pdfIn PDF document text
    • http://s4l.vn/storage/ckfinder/files/98637702958.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614f19c4e9c9a---gewotijekinugojetus.pdfIn PDF document text
    • https://cafesca.info/ckfinder/userfiles/files/jaxovigikaretiluge.pdfIn PDF document text
    • http://aokisuper.com/ckfinder/userfiles/files/zibozatujasaluvelopevu.pdfIn PDF document text
    • https://cuatudongsaigon.net/uploads/files/68163010346.pdfIn PDF document text
    • https://dom4m.lv/userfiles/files/sabituduzote.pdfIn PDF document text
    • https://floridahouselottery.com/test/userfiles/file/44170114276.pdfIn PDF document text
    • http://5lovestartw.com/CKEdit/upload/files/306049620.pdfIn PDF document text
    • https://ziyang100.com/userfiles/file/art_16330634481054.pdfIn PDF document text
    • https://drakbera.com/ckeditor/ckfinder/userfiles/files/74850946162.pdfIn PDF document text
    • http://cuanhuaabshanquoc.vn/files/75634525981.pdfIn PDF document text
    • http://sm.ac.th/ckfinder/userfiles/files/kudatemajozuvazomapuzodar.pdfIn PDF document text
    • https://esperidiaogomes.com/userfiles/files/32706232244.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=wmu+grading+scale+percentagesPDF 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_off0001c2f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C2F9 21860 bytes
SHA-256: df562d16cbf339ff46a8c85f1b9e9097523449a19c6ac031d00ff63cf499259b
font_01_sfnt_off0001fa54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1FA54 10828 bytes
SHA-256: 899cfac182967d16e3d71d06fdf51156b74a4d1c129ea40b8c648c155a2e0b8d
font_02_sfnt_off0002130f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2130F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1