Malicious PDF — malware analysis report

Static analysis result for SHA-256 557fdaa3096d0cb6…

MALICIOUS

PDF

75.2 KB Created: 2021-09-16 03:18:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6d33e9a90ac8ee5e8421e9c686483331 SHA-1: 8413913972e320f1d0a6c95cb289bb339ef9d480 SHA-256: 557fdaa3096d0cb6e5707b8f43b122aca993812dd2756b980c183c31580e2530
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many of which are hosted on disposable domains and utilize UTM parameters, indicating a link farm designed to obscure the final destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of an attack pattern that leverages external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://krisoc.ru/uplcv?utm_term=cornerstone+bible+church PDF link annotation
    • http://jeanthompson.nl/ckfinder/userfiles/files/25511748747.pdfIn PDF document text
    • http://avsa.org/sites/default/files/images/files/fogemi.pdfIn PDF document text
    • http://uts.edu.co/portal/app/ckfinder/userfiles/files/16499033119.pdfIn PDF document text
    • https://thisissati.com/userfiles/files/57900263871.pdfIn PDF document text
    • http://leaguengn.com/userfiles/file///4836668127.pdfIn PDF document text
    • http://jts-electrical.co.uk/ckfinder/userfiles/files/dimerijosew.pdfIn PDF document text
    • http://liderzy.natura2000.pl/imgturysta/files/moburibitomir.pdfIn PDF document text
    • https://valkexclusief.reviewz.eu/app/webroot/files/userfiles/files/79562535164.pdfIn PDF document text
    • https://giasidaily.com/uploads/userfiles/file/11615849175.pdfIn PDF document text
    • http://friulanapanini.com/images/file/9612243274.pdfIn PDF document text
    • http://slesnick.net/userfiles/files/bitufaxodabinifarolil.pdfIn PDF document text
    • http://okzawidow.pl/img/upload/files/35788347718.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/ff97eccede9b37f0eb6efc97363d2ff0/43883559086.pdfIn PDF document text
    • http://craftland.de/res/wysiwyg/file/47801180618.pdfIn PDF document text
    • http://aaykpn.com/uploads/editor/files/lotapotax.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/161427cd130b1b---12268393134.pdfIn PDF document text
    • http://grandviewgroupresort.com/upload/files/84432401559.pdfIn PDF document text
    • http://gjbbang.com/userData/board/file/77176233487.pdfIn PDF document text
    • https://karapinarinsaat.net/userfiles/upload/file/14147348056.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/3emam9n34rdo6nob8f8tijejat/ruzadudisesufelitineg.pdfIn PDF document text
    • http://sk-uralstroy.ru/uploads/files/pifabilolusibodujo.pdfIn PDF document text
    • http://vrakskodamnetice.cz/file/43667415056.pdfIn PDF document text
    • http://twgo8.com/uploads/base/files/202109101338054137.pdfIn PDF document text
    • https://hophamthaibinh.com/upload/files/85508912790.pdfIn PDF document text
    • https://pbanerjeeservices.4digitmagic.com/userfiles/file/lanifulobitejutinusudak.pdfIn PDF document text
    • http://dotykbylinky.sk/_subory/subory/24568340108.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_off0000c4b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4B2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dcc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCC4 16332 bytes
SHA-256: 972f548d3d10988ef08385ef49e0c0331bb4e4956d3d45d22bc5cb9e725ac26a
font_02_sfnt_off00010728.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10728 10436 bytes
SHA-256: 7346373ae48d5073a419651bc950922a173c350deb9e2128c648731ac376ca70