Malicious PDF — malware analysis report

Static analysis result for SHA-256 b52040e849db4b11…

MALICIOUS

PDF

74.7 KB Created: 2021-07-22 04:36:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 801a299b4c57b1d403ba2cdde038a44e SHA-1: dbf2451ffa0fd07c78ccfe64f26963f16d673291 SHA-256: b52040e849db4b1170eff4a4fec9902e275a7c866691c5c823e8a916f978ab37
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It functions as a link farm, containing numerous URLs that point to compromised WordPress upload directories and other potentially untrusted hosting locations. The primary purpose appears to be directing users to external, potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed82ca15d3---rixinowolep.pdf In PDF document text
    • https://rimsball.com/ckfinder/userfiles/files/88978723874.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160baa9d0dcf2b---susuna.pdfIn PDF document text
    • http://musorcentrum.hu/files/article/file/23534424645.pdfIn PDF document text
    • http://veraschwemmle.de/fckdata/file/viluzadi.pdfIn PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f3d6f67f683---mobigawusuleridameviduvif.pdfIn PDF document text
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/mo9nrk7s93r6h1hnhbbr8addb3/mopotapito.pdfIn PDF document text
    • https://anmimar.com/royal/userfiles/file/56650839118.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a466c69f13f---lolifefizulijususe.pdfIn PDF document text
    • http://hongshengfish.com/uploadfiles/2021051417351416573.pdfIn PDF document text
    • http://bociany.sk/media/file/joroxu.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/94732333401.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5302558684---kidixuz.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160b3c1eb62a85---63148957784.pdfIn PDF document text
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/bfab2d9b2ac3cc5bb8ffd5b3b049befa/16535594153.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/160e21098d472b---74579724700.pdfIn PDF document text
    • http://sk-uralstroy.ru/uploads/files/17205961002.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d4e5b8925d---78494808100.pdfIn PDF document text
    • https://neavocats.com/wp-content/plugins/super-forms/uploads/php/files/41b6cb7a053097d1bd65f9df7955fe69/45315406135.pdfIn PDF document text
    • http://tsg-vaganovskoe.ru/ckfinder/userfiles/files/78207748016.pdfIn PDF document text
    • http://kochamsushi.pl/UserFiles/file/rivonesanuliwixaguge.pdfIn PDF document text
    • http://likebarcode.com/image/files/20210705_134730.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071dd2c210ab---1110416268.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608930f24acdb---89506958238.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/160962fa2866c0---90516098761.pdfIn PDF document text
    • http://abwplazaview.com/uploads/files/28648602578.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=sat+practise+test+7+answersPDF 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_off0000c4ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4AE 10412 bytes
SHA-256: f6333a86132153d3659bba58e1cdb3df1bc1730c6b45346ca239ddbe67391a21
font_01_sfnt_off0000dc7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC7E 15532 bytes
SHA-256: e583c6704ed0327a4e6d226d421c83dd94bbf3e4b5bcced068397b1085bb116f
font_02_sfnt_off0001045d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1045D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1