Malicious PDF — malware analysis report

Static analysis result for SHA-256 ffa9f2d1338ab691…

MALICIOUS

PDF

84.8 KB Created: 2021-10-31 12:47:50 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 3f55dcef75b4f8ba0dd59d2cedcd3f50 SHA-1: 460404c5d5b7c8390e139d3d1191ca16a1e7c07d SHA-256: ffa9f2d1338ab691076e85f156fcf87675b35240f5ce122be275e0934c9646f9
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple distinct hosts, which is a common tactic for phishing or distributing further malware. The presence of external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly suggest a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.c-l-r-p.com/admin/ckfinder/userfiles/files/ligideduwegexa.pdf In PDF document text
    • https://pastelbuilders.com/userfiles/file/kimiguzebugofol.pdfIn PDF document text
    • https://dol-rtknetwork.com/uploads/files/87359825016.pdfIn PDF document text
    • http://waetsukai.jp/system/ckfinder/userfiles/files/18649509006.pdfIn PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/0c4224847d56b5fc5dd3090f3020ccdf/37725534791.pdfIn PDF document text
    • https://marblobaths.com/app/webroot/img/files/kaligodubop.pdfIn PDF document text
    • https://joinvita.com/neu/userfiles/file/60438555649.pdfIn PDF document text
    • https://beautifulhairstore.com/upload/files/67197358286.pdfIn PDF document text
    • http://yjccnc.com/upload/files/dezamagugin.pdfIn PDF document text
    • https://yenhuy.vn/upload/files/75093904020.pdfIn PDF document text
    • https://clubsecurite.fr/webroot/upload/files/vojafudidimijoxe.pdfIn PDF document text
    • http://bergepkolcsonzo.hu/userfiles/file/92608526635.pdfIn PDF document text
    • http://technestudio.eu/userfiles/files/33276635727.pdfIn PDF document text
    • http://richardchong.com/userfiles/files/radedapuziwa.pdfIn PDF document text
    • https://aporpeter.ro/userfiles/file/16156840037.pdfIn PDF document text
    • http://jin16888.com/userfiles/file/3266145050.pdfIn PDF document text
    • https://stancijanegrin.com/userfiles/file/91549420137.pdfIn PDF document text
    • https://deesudcoolingtower.com/userfiles/file/turazoxaseru.pdfIn PDF document text
    • https://zbmbudomont.pl/userfiles/file/ramorivexitozosuji.pdfIn PDF document text
    • https://brianhigbielaw.com/UserFiles/file/20527374772.pdfIn PDF document text
    • http://apvn.info/userfiles/file/siguxesanusowumenejuraxe.pdfIn PDF document text
    • http://slstudio.it/userfiles/files/22943563837.pdfIn PDF document text
    • http://www.og2c.com/images/file/26892253742.pdfIn PDF document text
    • https://ropaalmayoreo.com/images/userfiles/file/21968316335.pdfIn PDF document text
    • http://formel1vermietung.de/userfiles/file/wiranov.pdfIn PDF document text
    • http://an-professional.ru/img/files/file/vizifelap.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/RC0zOYPQW8A/uplcv?utm_term=what+is+the+plural+noun+of+moosePDF 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_off0000dfec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFEC 19964 bytes
SHA-256: 05cb2097d568184b1c350347169b3c6ec05d658e00b7ff9f753940ff05629fc2
font_01_sfnt_off000114da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012cf1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CF1 10716 bytes
SHA-256: d7efdcef6466174bb4bea1b660d840c754db7e3fcc9f7f881efeb5d7f1e2fee7