Malicious PDF — malware analysis report

Static analysis result for SHA-256 1736e2c1bb45e7f8…

MALICIOUS

PDF

83.7 KB Created: 2021-09-12 01:14:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 5a4e301220f53bd5bac8abf02ba0078f SHA-1: 2162e7f2539b402aef54ddc1cca8d7ce3108c3b1 SHA-256: 1736e2c1bb45e7f875fdedbdd883e1bbbb0f8ca5090157fee3191df147ce63ff
126 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic and the numerous extracted URLs suggest the document functions as a link farm, likely to redirect users to phishing sites or download further malware. No scripts were extracted, and the document body was unreadable, limiting further analysis of specific payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://chistogood.ru/admin/ckfinder/userfiles/files/4348264839.pdf In PDF document text
    • http://tutaylamhet.com/storage/ckfinder/files/libafofexugokaxiwo.pdfIn PDF document text
    • https://mirrorlink.com/public/files/files/nesopatijoneliki.pdfIn PDF document text
    • https://supermovi.com/userfiles/files/57247318981.pdfIn PDF document text
    • https://la-klamm.org/Files/files/38842408119.pdfIn PDF document text
    • http://dieukhactransam.com/uploads/files/16701888850.pdfIn PDF document text
    • http://odnoklassniki-files.ru/images/uploads/files/20715960688.pdfIn PDF document text
    • https://piataafacerilor.ro/app/webroot/files/userfiles/files/26059141243.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/72077198290.pdfIn PDF document text
    • https://csp-pub.com/stockages/files/79156558410.pdfIn PDF document text
    • http://pjzhengwang.com/upload/file/20210901_212742_188.pdfIn PDF document text
    • http://sakuragiramenandsushi.com/uploads/files/51708749498.pdfIn PDF document text
    • https://wrd13.com/force/file/98457302874.pdfIn PDF document text
    • https://n-zvuk.ru/upload/file/valobizuka.pdfIn PDF document text
    • https://rmp-traueranzeigen.de/cms/files/jagawegarobobafi.pdfIn PDF document text
    • http://hzaidele.com/images/upload/File/58590190635.pdfIn PDF document text
    • http://sicilyontable.it/userfiles/files/junola.pdfIn PDF document text
    • http://changrung.com/ckfinder/userfiles/files/zazozogowabaliwusuxidezi.pdfIn PDF document text
    • http://ikhmongol.mn/ckfinder/userfiles/files/jopibuten.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133a4c152ad2---53038277217.pdfIn PDF document text
    • http://newo.ru/files/files/bowebonemiwisowiroban.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/jikibatufejazeramuga.pdfIn PDF document text
    • http://theexplorerthai.com/userfiles/files/nubuwizowejasubanizosafol.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=page+plus+apn+settingsPDF 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_off0000e116.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE116 18608 bytes
SHA-256: bfdfca367d21a721f5cfbb2f346172e603235e02a7759fe737f04a4aff8ca666
font_01_sfnt_off000111cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000129e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129E4 10308 bytes
SHA-256: 6b739bd834072cac998a6b6ea22138e7facd6ea2d83c7e1e180812a41eb37c19