Malicious PDF — malware analysis report

Static analysis result for SHA-256 55e71fd7e702eeb8…

MALICIOUS

PDF

87.6 KB Created: 2021-09-17 22:02:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a06889794692535dae36be6194f86015 SHA-1: 4d692f0558ed100c72390fab75143731a39d5be1 SHA-256: 55e71fd7e702eeb8859e1c048075dbec828860a1b702d16c369dbaa9d991b276
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://swaving-stalinrichting.nl/ckfinder/userfiles/files/xitawaxuxibibonovipol.pdf In PDF document text
    • http://xn--h49al71atridzo.com/userData/board/file/38869564898.pdfIn PDF document text
    • http://ttc-investco.com/img/files/21608406370.pdfIn PDF document text
    • http://littlepearlbooks.in/data/eimages/file/ziweloferuputun.pdfIn PDF document text
    • http://bavlas.lt/ckfinder/userfiles/files/kunalasokezavafog.pdfIn PDF document text
    • http://innova-perila.ru/upload/files/98440807772.pdfIn PDF document text
    • https://299-45.com/CKEdit/upload/files/lozepeluxu.pdfIn PDF document text
    • https://lazdynumokykla.lt/userfiles/file/29485039169.pdfIn PDF document text
    • http://ranchobg.com/img/file/mokefamomudinademizov.pdfIn PDF document text
    • http://spartapr.com/images/upload/file/sunoxowobobebaw.pdfIn PDF document text
    • https://nbc.com.vn/ckfinder/userfiles/files/11409378876.pdfIn PDF document text
    • http://amandamaitland.com/images/file/fotobixanugip.pdfIn PDF document text
    • http://baove24h.org/upload/files/7007490150.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16135caac40d1c---37689596201.pdfIn PDF document text
    • https://pelicanfinancialnetwork.net/ckfinder/userfiles/files/15180219941.pdfIn PDF document text
    • https://rockeit.com/userfiles/file/zitizijilevudox.pdfIn PDF document text
    • http://gzmzwl.com/Uploadfiles/files/murum.pdfIn PDF document text
    • https://topclassgardening.nl/images/file/73793824444.pdfIn PDF document text
    • http://lycee-elm.com/userfiles/file/24113624305.pdfIn PDF document text
    • https://bachson.net/upload/file/38548913161.pdfIn PDF document text
    • https://kolegium.inaheart.org/upload/files/60396742336.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/f9a85ad39a1c314636d44d48ebdab76d/41557449921.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161435298779be---lufusuwamagemikurulatuku.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=data+from+pdf+to+excelPDF 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_off0000f04d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF04D 18520 bytes
SHA-256: d24f5b033a7d6640bfcbb43c29697f9be88857297752e2ecccc8f18c0b577102
font_01_sfnt_off000120c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120C7 10520 bytes
SHA-256: 96a7fd779a5e1020a1b5cdf59955bfd4b1921b43d34983384d5f633ee4d527ae
font_02_sfnt_off000138cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x138CB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1