Malicious PDF — malware analysis report

Static analysis result for SHA-256 85cfb9660d2bd384…

MALICIOUS

PDF

77.6 KB Created: 2021-07-18 16:44:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 89991c1ef11de38cd9cdc3b8b0835c34 SHA-1: c9015b63a45bfe8f88e65c76feb66d661f123658 SHA-256: 85cfb9660d2bd3845564a32ecf56bcd0d5adb317d6731f243c27920b70a942e4
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to compromised CMS upload directories, indicating a link farm or redirection strategy. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the presence of multiple links to potentially malicious or compromised sites suggests an attempt to lead the user to a malicious resource.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9829

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://pphjako.pl/userfiles/file/sefomafasike.pdf In PDF document text
    • http://archgeo-leszno.pl/uploads/userfiles/files/dulopepenomo.pdfIn PDF document text
    • https://ambientltg.com/wp-content/plugins/super-forms/uploads/php/files/a4cb4ebb8cb1dd36bada86ac369ad1aa/bizaf.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/cc5c49ba1b233c7922a6539a1b7e969f/faroxajozisufimibigalefo.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c104d23cf59---lobewetogemujugatuz.pdfIn PDF document text
    • http://sun-tes.ru/files/file/dakojuva.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095ffcb56593---rurelafazisoros.pdfIn PDF document text
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/o8i1qrkqm70n75qcp9s455o8i6/gejexebekamapubunupof.pdfIn PDF document text
    • http://www.aadhar-interior.com/userfiles/file/wututapowovifituzof.pdfIn PDF document text
    • http://xn--o79av69abka850ab6c.com/upload/file/202107011921274509.pdfIn PDF document text
    • http://biotop-zamosc.pl/userfiles/file/11224675455.pdfIn PDF document text
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/5bd288973326c70b0d21c8729aade0c8/33582064969.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/qjitmmu2u5k4tcdtnfru4s67a1/fojiruzefudefodaloro.pdfIn PDF document text
    • http://superpart.com/files/70738558587.pdfIn PDF document text
    • https://unosms.us/userfiles/file/13798713498.pdfIn PDF document text
    • https://europeancustomtailor.com/wp-content/plugins/super-forms/uploads/php/files/a2809f1c2ff80ed3235b89e13ced72cd/23480723370.pdfIn PDF document text
    • http://www.alfapilates.pl/upload/file/sunejodapakexeniwinek.pdfIn PDF document text
    • https://protechlighting.com/wp-content/plugins/super-forms/uploads/php/files/dbbcf24337a59ef6a53f68191de3b6b5/vovikupoziz.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/981vb04ni634983iban233hhas/24648246481.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/9d674544a2038bfe18b144225e5a9d96/giwiradufewa.pdfIn PDF document text
    • http://m4klynchburg.org/clients/3/34/34420611de4c9c7593cf5e5fe12de6df/File/68355259605.pdfIn PDF document text
    • http://odnoklassniki-files.ru/images/uploads/files/71583137878.pdfIn PDF document text
    • http://dytac.hk/userfiles/70870562764.pdfIn PDF document text
    • http://nuestratierrapremios.com/campannas/file/mupogojuwafivotasetusar.pdfIn PDF document text
    • http://dsraxys.com/uploads/jobesedezonoguxixerawo.pdfIn PDF document text
    • https://armenia4d.com/contents//files/galufifumimemilatutili.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=blue+chip+limitedPDF 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_off0000cb85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB85 17548 bytes
SHA-256: a2e163e81410255c6254a7555a1275d27422371e99afdfff0619c78e0f9f8291
font_01_sfnt_off0000f861.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF861 10276 bytes
SHA-256: 293c5bcb6ae6b96314c80a891eadc293b197422cae60a8db0cde05c4797ce9b1
font_02_sfnt_off00010f7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F7F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1