Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f1a45252cc7e315…

MALICIOUS

PDF

74.4 KB Created: 2021-09-19 09:37:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b7dfbd835f3e98cecbd308db927b631a SHA-1: d9a028b23fdbd23371cfdb4fff5203571084eb68 SHA-256: 8f1a45252cc7e3159d2c386f2e845cace4564378ba3e75e9b6d07f4a2a80fecf
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains numerous links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.jasolasia.com/image/upload/File/tavubagotutujikofixuvozu.pdf In PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613d1671cb624---66657909182.pdfIn PDF document text
    • http://aktien-analyse.de/images/File/kujavipituderupar.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/b8e4f45325298c070a386df1e0d5a0eb/44733048743.pdfIn PDF document text
    • http://saluteebenesseresas.it/userfiles/files/20679778537.pdfIn PDF document text
    • http://henca.com/files/details/file/14796337199.pdfIn PDF document text
    • https://worldtradezone.com/userfiles/file/muwiwugu.pdfIn PDF document text
    • http://xn--80ahcjevtqq.xn--p1ai/ckfinder/userfiles/files/seburedugosuzafasixodaz.pdfIn PDF document text
    • http://ahdongjiu.com/upload_fck/file/2021-9-17/20210917161511983186.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab3d683e4e---24936472987.pdfIn PDF document text
    • http://selfmadefilms.nl/userfiles/files/kakagoxufuziguxedawarix.pdfIn PDF document text
    • http://langyupharm.com/upload/files/vutomepejidiwamajose.pdfIn PDF document text
    • http://kpdb.org/userfiles/files/81337324360.pdfIn PDF document text
    • https://aljazeerahdrilling.com/userfiles/files/17663746317.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1613edb44ada36---topibu.pdfIn PDF document text
    • https://bravo-hk.com/userfiles/file/xewegigabimedunavuf.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/2285012274.pdfIn PDF document text
    • https://kabelkyaobuv.sk/editor_uploads/files/vopetujezabosawipemip.pdfIn PDF document text
    • https://airxps.com/userfiles/files/patumawefifoxikilibuf.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16139eabe52f35---42476800547.pdfIn PDF document text
    • http://soosanfix.com/upload/fckeditor/file/lisuzizewigajiwimugubeko.pdfIn PDF document text
    • http://studiopol.com/userfiles/files/rumefitulane.pdfIn PDF document text
    • http://www.corazondelsol.es/ckfinder/userfiles/files/ratepedamagaxosarukak.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=harry+potter+and+the+sorcerer%27s+stone+123PDF 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_off0000bde3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDE3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d5fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5FA 10956 bytes
SHA-256: 643723f95edb6477013f6b551014d42b7c4638b0b511300f9cbc394c84e07d68
font_02_sfnt_off0000ef80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF80 17460 bytes
SHA-256: 0a210624a0f06a0d9a3b502769f113fa048f03c3fa75dfc43bb50a0269ef4119