Malicious PDF — malware analysis report

Static analysis result for SHA-256 6cf490dcf504d658…

MALICIOUS

PDF

84.1 KB Created: 2021-09-16 18:43:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 82f71558afd4b87728bae60c76f7f54b SHA-1: a8dcc7df6061f807b327ff0b6ef0c96db90fa340 SHA-256: 6cf490dcf504d6583ecce8dca1b85c0d099f8c2f3d2cf93546d4e34a2093a81e
126 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to a link farm hosted on disposable domains, a common tactic for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://ist-lb1.istanajp.com/contents/files/tofosutifupipita.pdf In PDF document text
    • http://mail.me.ntou.edu.tw/ckfinder/userfiles/files/20210913_200550.pdfIn PDF document text
    • http://farmandari-sarvestan.ir/images/news/files/73138869178.pdfIn PDF document text
    • https://firmabudowlanawalczak.pl/web/uploads/files/gijarekagevibesufupe.pdfIn PDF document text
    • http://palyavalaszto.hu/teszt/upload/file/36498247321.pdfIn PDF document text
    • http://www.kymkarajok.net/tiedostot/files/tijowileworobizak.pdfIn PDF document text
    • http://www.thaitofu.com/image/upload/File/fivila.pdfIn PDF document text
    • http://orzo.cz/uploaded/files/zujoriduwo.pdfIn PDF document text
    • https://franciscovalles.comtraining.cl/userfiles/files/86312880261.pdfIn PDF document text
    • http://self119.net/upload/userfiles/2021/09/files/210912015107.pdfIn PDF document text
    • http://wienbildarchiv.com/upload_files/files/rotorovizezawetevud.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16135c85236e59---xosekojaxageles.pdfIn PDF document text
    • http://gzmzwl.com/Uploadfiles/files/murum.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136aa88c7184---49417671579.pdfIn PDF document text
    • http://gsmontaggi.it/userfiles/files/jokezofojojusomarufawe.pdfIn PDF document text
    • http://imobiliariaimperio.com/files/files/59992719615.pdfIn PDF document text
    • http://seasonmediagroup.com/pic/file/73461259623.pdfIn PDF document text
    • http://www.sm.ac.th/ckfinder/userfiles/files/37504872415.pdfIn PDF document text
    • https://zoldlepes.hu/userfiles/file/gobavugewade.pdfIn PDF document text
    • http://zhouzhuank.com/v15/Upload/file/202191493454187.pdfIn PDF document text
    • http://uran-berlin.com/userfiles/file/79764060331.pdfIn PDF document text
    • https://emilline.dk/ckfinder/userfiles/files/54019598706.pdfIn PDF document text
    • http://ccsilver.kr/files/fckeditor/file/266829156613a95e477b0a.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+root+samsung+galaxy+s4+without+computerPDF 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_off0000e1c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f9dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9DD 11292 bytes
SHA-256: 31f58116483ab28c2a2da3945a9f9ea10f1ad7c02d0d286cbbe343cd01218015
font_02_sfnt_off00011457.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11457 17696 bytes
SHA-256: 08e77f0664e4041aa9460373d7dacbc4adce387a1b0b8893ed006cec1b248f7c