Malicious PDF — malware analysis report

Static analysis result for SHA-256 dd3899070a1b0ec1…

MALICIOUS

PDF

88.7 KB Created: 2021-09-23 02:25:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c951e89af92793d11a8718363a5a4a30 SHA-1: 7a350be96742fbd76dc01bc8a8f7efc36b75869a SHA-256: dd3899070a1b0ec1d30dd96a095a62dffce98748fbf572f5f0f3968c77cf2148
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as a malicious PDF by ClamAV and an ML classifier. Heuristics indicate malformed streams and link farms pointing to potentially compromised websites. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to external resources, likely for phishing or scam purposes. The presence of multiple unknown URLs and the 'link farm' heuristic contribute to the assessment of a phishing or scam attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6191

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://forspeed.cz/ckfinder/userfiles/files/80778377422.pdf In PDF document text
    • http://www.monts.sk/upload_images/file/68395533601.pdfIn PDF document text
    • https://baxsporthorses.com/userfiles/file/85546519539.pdfIn PDF document text
    • http://vinczeandlaszlo.com/upload/pizudikajovezo.pdfIn PDF document text
    • http://niestachow.pl/data/aktualnosci_imgs/file/tojobobifimazulun.pdfIn PDF document text
    • https://kurtoglumob.com/upload/file/tibowavegerurudidara.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613d299603ad5---40825802172.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614634a7e8798---30618579727.pdfIn PDF document text
    • https://almuhja.com/ckfinder/userfiles/files/fijinajatijijuzarew.pdfIn PDF document text
    • http://bk-plus.at/userfiles/files/xupesavikop.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f4e05a7355---kezuwajalizudoni.pdfIn PDF document text
    • http://grafichesirio.com/userfiles/files/lakajuremabafigul.pdfIn PDF document text
    • https://schmitz.cz/res/file/37342929882.pdfIn PDF document text
    • http://wuyioutdoor.com/userfiles/file/71532791534.pdfIn PDF document text
    • http://dorrstrechy.cz/UserFiles/File/wavipupelamefokeguzejon.pdfIn PDF document text
    • http://artikos.pl/userfiles/file/bogot.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/0bf7d89c5941c8831e9ccff84c17e20a/27188685607.pdfIn PDF document text
    • https://saunadlaciebie.pl/userfiles/file/jidikiposipudubiwinidivil.pdfIn PDF document text
    • http://twinmd.ru/userfiles/file/sizedenojunulusasew.pdfIn PDF document text
    • http://bilafafafa.com/shopadmin/upload/files/dogunakorogorefabo.pdfIn PDF document text
    • http://serramentisiciliano.it/userfiles/files/fekolumo.pdfIn PDF document text
    • http://kopdesign.nl/userfiles/file/33654789178.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=top+ten+big+country+in+the+worldPDF link annotation
    • 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_off00010258.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10258 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011a6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A6A 17256 bytes
SHA-256: 69395ecebce7b8fc9fbe176d5ab12d0618207ee592729bcb449f84007f6cbdbf
font_02_sfnt_off00014729.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14729 10864 bytes
SHA-256: 4cbfd4980d9b7db41bcfabd5989e1365e780851eb753c59518738a526e86dbf7