Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a5d8d8ba1548d29…

MALICIOUS

PDF

83.5 KB Created: 2021-07-01 14:00:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 23ee39aa15e424012c2cdddb0e8b53c3 SHA-1: eb6a9276ff70b92d584c82a942836fa30c18ff3f SHA-256: 4a5d8d8ba1548d29705e7af927c5d149be2b3d7da1999388f64c4b81718177a2
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file exhibits characteristics of a malicious document, including multiple heuristics indicating it's part of a link farm pointing to compromised websites. The ML classifier strongly flags it as malicious. While no scripts were directly extracted, the presence of numerous external URLs suggests the document's primary purpose is to redirect users to potentially harmful sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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 https://laborke.ru/uplcv?utm_term=the+resistance+of+a+thermistor PDF link annotation
    • http://mea-travel.pl/userfiles/file/24878334128.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/160806e0b832b7---vutola.pdfIn PDF document text
    • https://carlojans.com/cms/file/fasojivi.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609c99f513a9d---dexojufepij.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/5e0bfde45c568358d464f9f91c527d2f/repopodewapekatigoxipexew.pdfIn PDF document text
    • https://www.stjohnhomelessshelter.org/wp-content/plugins/super-forms/uploads/php/files/0711c1eacd3ed42fea55e6af2fd37273/71272184808.pdfIn PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/kjgb5hgg8tv28bo5j42k46ti6k/jujokugoxasibuso.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607cc9be1cb87---jenaredanuzeputeserur.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607124756732c---24076877557.pdfIn PDF document text
    • https://reniuved.it/file/43105377511.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/fbde7b0f72141b5d19f36c32cec772f1/zumimupofupewapokuxini.pdfIn PDF document text
    • http://sl1971.com/clients/5/51/517263f0417f9379c67e6eba0e0bdfe8/File/zukixivatobabisi.pdfIn PDF document text
    • https://stillwaiting.org/userfiles/file/sufemegolupata.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/valetimu.pdfIn PDF document text
    • http://abpaluso.com/upload/file/todawusezunagoxatazozad.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fbcd193e68---zopovuzevakumumez.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5134d1a6be---34331862261.pdfIn PDF document text
    • http://kleiberit.ru/files/file/teriviwerivuvo.pdfIn PDF document text
    • http://urgentcarepb.net/userfiles/file/jumadixotovut.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/bec55c923bef9337d04c9634d08faeb5/lelofot.pdfIn PDF document text
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/3m3r1a7ra52egl8plua03jgjr6/povudokolaw.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_off0000e2e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2E3 17640 bytes
SHA-256: f9ee582ef68abba645adc90b5d8defa7e6d2d42f59e0df5f284ff7ee8a32a0bf
font_01_sfnt_off00011100.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11100 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012917.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12917 10516 bytes
SHA-256: 15f513e8e07ecdeade49edb809ea332dc63f6acc078489db4b7cced0c683d59b