Malicious PDF — malware analysis report

Static analysis result for SHA-256 605d2b40c1e096f0…

MALICIOUS

PDF

77.0 KB Created: 2021-09-12 05:02:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 10921464508a77543b50baf296705f3e SHA-1: 66f52b68d0cfe7d61ffc2af0a2136ef60040b5dd SHA-256: 605d2b40c1e096f03463860fe5f037661415c6cbb42a01e4984dde21feb21e2e
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. The PDF contains numerous external links, many pointing to disposable hosting, suggesting a link farm or phishing lure. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards techniques used for initial access via spearphishing attachments, potentially leading to further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://gancza.pl/userfiles/file/74574702436.pdf In PDF document text
    • http://www.bluewhaleline.com/image/upload/File/zaguxipeziwasozufavi.pdfIn PDF document text
    • https://kawanmto.net/contents/files/vijab.pdfIn PDF document text
    • https://hattoco.vn/images/ckeditor/files/jokezetukumisuvemiwufane.pdfIn PDF document text
    • http://lulanjina.net/upload/files/70122447256.pdfIn PDF document text
    • https://bdaudit.ro/userfiles/file/68301808145.pdfIn PDF document text
    • http://spl-designs.com/ckfinder/userfiles/files/bilib.pdfIn PDF document text
    • http://iraneto.com/basefile/iranetocom/files/15818780656.pdfIn PDF document text
    • http://filipdegreef.be/uploads/files/muwipugogevelugekusupe.pdfIn PDF document text
    • https://nepalmicrofinancesummit.org/userfiles/files/31619640873.pdfIn PDF document text
    • http://sumisaedu.com/FileData/ckfinder/files/20210908_356B1B1BA8D6A5F0.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/85a393e3bd41b12dc0427c4b1dba54f4/duvub.pdfIn PDF document text
    • http://irina-beha.com/ckfinder/userfiles/files/10750127885.pdfIn PDF document text
    • https://karatenarrewarren.com.au/ckfinder/userfiles/files/vajadosibugi.pdfIn PDF document text
    • http://gotween.com/userfiles/file///fanivitopit.pdfIn PDF document text
    • https://thebookonpersonaltransformation.com/FCKeditor/file/pugajabuno.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a0f8ad05bc---wipeturabufutelabikulewim.pdfIn PDF document text
    • https://castilloexterior.org/ckfinder/userfiles/files/80066318225.pdfIn PDF document text
    • http://lumieretvie.com/userfiles/file/22327723233.pdfIn PDF document text
    • http://elliptical-trainers.ru/ckfinder/userfiles/files/39348317764.pdfIn PDF document text
    • http://belv.ru/userfiles/file/bepubosokusuzegop.pdfIn PDF document text
    • http://belovosushi.ru/files/gibetevafafujore.pdfIn PDF document text
    • http://www.europesolidaire.eu/userfiles/files/fupalanavipi.pdfIn PDF document text
    • https://fulzugaskozpont.hu/files/zavuxavagarinibexufasukor.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=the+hole+in+the+ground+ytsPDF 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_off0000c830.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC830 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e047.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE047 10544 bytes
SHA-256: e9dbdd10eb75206fd5f3ca03486f06e73c7b5739dfaef0ae63d4b366197713bf
font_02_sfnt_off0000f80e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF80E 17772 bytes
SHA-256: 50e1580881e41ae6caead31515352642edc5c8fe607811d5086a2ec01517b523