Malicious PDF — malware analysis report

Static analysis result for SHA-256 a59f065c9b72e02a…

MALICIOUS

PDF

98.8 KB Created: 2021-09-11 04:07:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: dc36330cf68b81359c8fcfebd2ff0c1e SHA-1: 51ebd07acc2159f985b97a1a77c7af0b125b9c4a SHA-256: a59f065c9b72e02a487e7123339f581bcde2d23442c13be153b889afbbba48ae
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URLs, many hosted on disposable domains, suggesting a link farm or phishing lure. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically flags this behavior, and the embedded URL heuristic confirms the presence of external links. While no scripts were explicitly extracted, the nature of the heuristics and the verdict strongly suggest the PDF is designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 https://allytemp.ru/uplcv?utm_term=principles+of+economics+twelfth+edition+pdf PDF link annotation
    • http://studioscoponi.eu/userfiles/files/23037056760.pdfIn PDF document text
    • http://hoangle.vn/uploads/userfiles/file/76058808645.pdfIn PDF document text
    • http://anneadamslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jotelajifuvorojo.pdfIn PDF document text
    • http://www.iuoelocal870.com/kaizen/ckfinder/userfiles/files/mifiwutegakesofutipezipo.pdfIn PDF document text
    • http://goodtraefarm.com/ckupload/files/51349968084.pdfIn PDF document text
    • http://locum-system.pl/userfiles/file/liwukowufimiru.pdfIn PDF document text
    • http://www.sloepverhuur-debiesbosch.nl/upload/files/10043190402.pdfIn PDF document text
    • http://www.somdattabasu.com/fckimages/file/wukuwabimujabiseseti.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/161304a94b2535---84371743612.pdfIn PDF document text
    • http://terrietanaka.com/library/files/70782178565.pdfIn PDF document text
    • https://discovercefalu.it/_data/images/file/guxiwufi.pdfIn PDF document text
    • https://bostoncake888.com/UserFiles/files/pisovaperozux.pdfIn PDF document text
    • http://hungthanhauto.com/luutru/files/38525695967.pdfIn PDF document text
    • https://karapinler.com/calisma2/files/uploads/gekapemobad.pdfIn PDF document text
    • http://thankschicken.com/uploads/files/xivubur.pdfIn PDF document text
    • http://osayit.com/images/file/gajekagi.pdfIn PDF document text
    • https://uleiuri.ro/userfiles/file/lewasaragirozetagozodi.pdfIn PDF document text
    • http://forti.in/userfiles/file/keletemapul.pdfIn PDF document text
    • http://malbreil.com/userfiles/file/zumikemejulik.pdfIn PDF document text
    • http://arabic.cz/ckfinder/userfiles/files/wetas.pdfIn PDF document text
    • http://tz5168.com/uploadfile/image/2021/09/01/file/20210901_072025_167.pdfIn PDF document text
    • http://gsprojekt.eu/userfiles/files/97913147140.pdfIn PDF document text
    • http://clinton.abwingsmd.com/uploads/files/81034776394.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_off00011c58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C58 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001346f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1346F 10812 bytes
SHA-256: e205868e8eff0f1465f5c6c0d237fd51436e2a8afd82630d347b786a0623a4da
font_02_sfnt_off00014d2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D2B 18448 bytes
SHA-256: 34320c249fa55c30a935a4b617db9c705447c167a8ac9a2ba476906bd4e9d37e