Malicious PDF — malware analysis report

Static analysis result for SHA-256 0b81b35901d51710…

MALICIOUS

PDF

93.2 KB Created: 2021-06-28 11:56:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e81e38716778c5eb0e71d602185e49ba SHA-1: 7248845ee61b2b5af8adc19484fa61b1641f3cb1 SHA-256: 0b81b35901d5171081b6ed23b65a6c42d5a4810743dcac12c1a36dadacb233f1
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm for SEO manipulation or malicious redirection. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent behind the link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://olsztyntransportmedyczny.pl/userfiles/file/70866388265.pdf In PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4446f0f6af---sumav.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/s7f2g9tbtqg0ibdl1st17m10ke/zamasutifamokemabivaxete.pdfIn PDF document text
    • http://fuga-hotel.com/CKEdit/upload/files/bigisoliwurulakagewu.pdfIn PDF document text
    • http://reutlinger.pl/userfiles/file/41673679050.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/cfc1dc8a75eff65f113332670d466070/fojati.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/d3b6310416888dc6775de4345bdc5d52/42138728935.pdfIn PDF document text
    • http://appletechsolutions.com/userfiles/file/6421346183.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce77d46baa4---30176804246.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16085f2cd431bd---kerefiwuzexu.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1102412378---xodagovefolonotorufizute.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160996e56326b8---webenimimo.pdfIn PDF document text
    • http://chiangmai-clean.com/user_img/files/jewotavibaxaramosefure.pdfIn PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b1280cab89---60482842004.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/160853ff6c07fc---75499073713.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/160725a504d11a---godadikizeduvu.pdfIn PDF document text
    • http://phaptangpgvn.net/app/webroot/upload/files/ragefubalarotosefunuxexa.pdfIn PDF document text
    • http://cunningham-reunion.com/clients/7/73/7399477c88ef979e1ad3ac38e42cffcc/File/6692913043.pdfIn PDF document text
    • http://china-engine.net/ckfinder/userfiles/files/malusixosonakefel.pdfIn PDF document text
    • https://chetanaus.org/bheru/uploadfiles/file/61098762624.pdfIn PDF document text
    • https://dudikom.pl/userfiles/file/zupudarupetowiniv.pdfIn PDF document text
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/v65h3temd8qg3u0msqj7m6ufil/kijok.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=apk+streaming+appsPDF 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_off00010ada.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ADA 10504 bytes
SHA-256: 4bdad40802595278ea6c24cb962d281fcfe85c7243f2171adad253e937a0a3c9
font_01_sfnt_off000122cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122CF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013ae1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AE1 17144 bytes
SHA-256: c2361c587daff873f5617b5ab70568d3be646fc5b5a5dab965383c40c2151b01