Malicious PDF — malware analysis report

Static analysis result for SHA-256 16a255297d1e2022…

MALICIOUS

PDF

84.4 KB Created: 2021-08-16 22:17:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: cb9252609339e9acd6a2b2a3d629f841 SHA-1: 9178bbf84fa4c4af9b6a41ad75a8be4306d399d5 SHA-256: 16a255297d1e202273b5d67d77280530e6669d6e79b4e5773cb33c3356d8f513
156 Risk Score

Malware Insights

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

The PDF file contains a link farm, with numerous embedded URLs pointing to various websites, many of which appear to be compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO manipulation. The presence of multiple distinct hosts and the nature of the URLs suggest an attempt to distribute malicious content or traffic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.niziointerior.pl/upload/file/rafenusapirak.pdf In PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a0c111dce54---70442536802.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608251d345099---22896538748.pdfIn PDF document text
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/1bfd646d664339a6e5c9bf2c3bf98b01/55843767403.pdfIn PDF document text
    • http://gw73patriots.com/clients/1/1e/1ed986c9d410becccfd9995a8318e329/File/44052701000.pdfIn PDF document text
    • http://eprdel.cz/userfiles/file/pudaxejiwisefotajojotagul.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c5de6eb4efb---sobajabuxezezotoxiwizonak.pdfIn PDF document text
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/29scv0r6cgt06l2vu6ar7mdhcb/36014947062.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/ef06rolcpedit4s8cskq82bl12/16838382546.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16081900f6348b---99339283448.pdfIn PDF document text
    • https://mimpishiosatu.com/contents//files/64708273147.pdfIn PDF document text
    • http://www.vinoplaza.nl/img/upload/files/61252423973.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d6191ac753---mixojekiw.pdfIn PDF document text
    • http://gibisch.org/files/files/xinugetogiz.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083685d09e92---fuluwogupizasula.pdfIn PDF document text
    • http://spodne-pradlo-2bpoint.sk/UserFiles/File/56906876978.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606f566bce3fa---jegolag.pdfIn PDF document text
    • https://www.loscam.com/lib_common/ckeditor/ckfinder/userfiles/files/bupuvufaxekajuxumowuwo.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0a127b6be---2000108612.pdfIn PDF document text
    • http://shangrilatheshow.com/ckfinder/userfiles/files/9907783627.pdfIn PDF document text
    • http://youngthisyear.com/ckfinder/userfiles/files/44332378861.pdfIn PDF document text
    • http://studiospazioambiente.it/userfiles/files/35838776863.pdfIn PDF document text
    • https://proxus.nl/file/71721194381.pdfIn PDF document text
    • https://palcev.ru/userfiles/file/24279506779.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=periodic+table+flashcards+printable+freePDF 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_off0000e627.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE627 10860 bytes
SHA-256: fb5fd25248b6f07b0171b4b87df3d0107b8440d449ce22d9e5456beb611df796
font_01_sfnt_off0000fee9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEE9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000116fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116FB 16704 bytes
SHA-256: e662b19541c84d669482f74cf0b7e3b20a8a048689ae8f0bca394ae241d3aae0