Malicious PDF — malware analysis report

Static analysis result for SHA-256 c28d77c33db260b4…

MALICIOUS

PDF

68.8 KB Created: 2021-09-27 00:32:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 7111acbf3aba82f18268f6a3986c2470 SHA-1: a3a6b5a301fa11c1c05159dedce534765735bf6c SHA-256: c28d77c33db260b4ff6c108edcf47a1ff08d6783a97474ae963c4e3d0f8fc29a
126 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous external links to other PDF files. The presence of 'utm_term' parameters in some URLs suggests tracking or redirection, common in phishing and scam operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ip-malkov.ru/uploads/files/9885997561.pdf In PDF document text
    • https://lanegarrett.net/userfiles/file/59877116073.pdfIn PDF document text
    • http://josquin-capella.de/download/fedetedajujo.pdfIn PDF document text
    • https://infoenergie-loire.org/userfiles/file/20781609894.pdfIn PDF document text
    • http://xn--e1aazeoc7d.xn--p1ai/images/shared/file/12235074600.pdfIn PDF document text
    • http://www.lukoilmarine.com/ckfinder/userfiles/files/18354265610.pdfIn PDF document text
    • http://bijverhoeven.nl/uploads/files/xatekesowivuwaxefi.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613dfb6923c01---wugezirimoz.pdfIn PDF document text
    • https://akapacha.com/userfiles/file/45443619722.pdfIn PDF document text
    • http://sinoorchids.com/image/file/fedasudetoredov.pdfIn PDF document text
    • http://entryexpress.online/chapter_images/files/12303574942.pdfIn PDF document text
    • http://yh-nutri.com/filespath/files/20210908151324.pdfIn PDF document text
    • http://bigdoughpizza.com/uploads/files/77684374844.pdfIn PDF document text
    • https://ww150007.linebot.net/upfile/files/20210901233521.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/nipiworonuruvabugimizisev.pdfIn PDF document text
    • http://twfbs.com/ckfinder/userfiles/files/8395916223.pdfIn PDF document text
    • http://aumnat2car.com/ckfinder/core/connector/php/upload/files/kirupu.pdfIn PDF document text
    • http://www.impactit.in/ckfinder/userfiles/files/vogaxupaxuseraxibapovota.pdfIn PDF document text
    • https://self-storage.sg/images/uploadedimages/file/vemejatogaranotiz.pdfIn PDF document text
    • http://giaydantuongphongngudep.com/images/news/file/xoxakofudoluwojebukeku.pdfIn PDF document text
    • http://innospectrum.eu/hirlevel/file/ladamupusa.pdfIn PDF document text
    • http://noithatlekhanh.com/Images_upload/files/17583219873.pdfIn PDF document text
    • http://fmmvn.net/userfiles/files/60613287390.pdfIn PDF document text
    • http://daming-school.com/userfiles/file/lijisipeboxujiwewimubim.pdfIn PDF document text
    • https://weishinclinic.com/uploads/files/202109200914505816.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=hungry+shark+world+free+gemsPDF 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_off0000b081.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB081 14408 bytes
SHA-256: cd5e3ae596f1035e0cb8981d995988bea1845b9f1cf1a5fdb3dfab591d68b124
font_01_sfnt_off0000d485.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD485 10992 bytes
SHA-256: 4e01869403bb57f9ed992a79a3a5b58f2659c533662c917c3560ff62aba0d35d
font_02_sfnt_off0000edb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1