Malicious PDF — malware analysis report

Static analysis result for SHA-256 a73baa859607604f…

MALICIOUS

PDF

75.5 KB Created: 2021-09-12 09:06:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c4848de442face3af6624fd0ce4910f6 SHA-1: 43e48e58d2f88ec6568adc58785704fd1b156ef5 SHA-256: a73baa859607604f3553997bf1ee2ec39969c2236efec3d08e813c963a643e71
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF contains numerous embedded URLs pointing to external sites, suggesting a phishing or malware distribution scheme. While no scripts were explicitly extracted, the PDF structure and numerous external links strongly suggest it's part of a larger attack chain, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9901

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 https://weddingitaly.jp/images/file/66128975685.pdf In PDF document text
    • https://satellietgroep.nl/userfiles/files/60053033401.pdfIn PDF document text
    • https://firesystem.ro/imagini_ws/72993468933.pdfIn PDF document text
    • http://abwva.com/uploads/files/57750354679.pdfIn PDF document text
    • http://teraval.cz/res/file/risaposok.pdfIn PDF document text
    • http://www.tecnobor.com/ckfinder/userfiles/files/fajolugelu.pdfIn PDF document text
    • http://bordahusfeldolgozo.hu/editor_up/fojufubalilanazovonev.pdfIn PDF document text
    • https://osiindia.org/ckfinder/userfiles/files/futazisozirezuzesefojos.pdfIn PDF document text
    • https://produktybhp.pl/pliki_user/File/xafizorepamesirewaxiwesu.pdfIn PDF document text
    • http://boras-sjuharad.boj.se/uploads/userfiles/files/40682397148.pdfIn PDF document text
    • http://horizonpestservices.com/userfile/79810321723.pdfIn PDF document text
    • http://trans-serwis.com/userfiles/file/24851169798.pdfIn PDF document text
    • https://tsegypt.com/file/49416563402.pdfIn PDF document text
    • https://topclassgreenery.nl/images/file/93655343634.pdfIn PDF document text
    • http://kythuatviet.vn/uploads/userfiles/file/87777769302.pdfIn PDF document text
    • http://holdemigny.fr/ckfinder/userfiles/files/mexevidagusega.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb22b0403b---38529999592.pdfIn PDF document text
    • https://implant-drill.com/userfiles/file/90013949590.pdfIn PDF document text
    • https://fptica.ru/images/file/selokuxevazativ.pdfIn PDF document text
    • http://aldobini.it/userfiles/files/7798051214.pdfIn PDF document text
    • http://thy-environment.com/userfiles/files/46764587393.pdfIn PDF document text
    • https://dermatologie-chamonix.com/userfiles/file/zewolorepusuve.pdfIn PDF document text
    • http://metalltechnik-kutschi.at/maxozipelibopovivuwupijil.pdfIn PDF document text
    • http://domainecomps.com/documents/files/51409227720.pdfIn PDF document text
    • http://jmestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/buginak.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/c6b43a17ede67ac88f461a8fb46595c6/62178844280.pdfIn PDF document text
    • http://brain-sh.tw/upload/file/18694009204.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=minecraft+free+play+androidPDF 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_off0000c30c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC30C 17344 bytes
SHA-256: 4f572a37c4d282afe99851d2974756089c44592a5d8a35617024d55f16fbe812
font_01_sfnt_off0000efa5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000107bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107BC 10552 bytes
SHA-256: 3bde024ab145084da8ff4937206326fe71bd87d9396b0615af9c8fb7ed81082f