Malicious PDF — malware analysis report

Static analysis result for SHA-256 35530f39bcf5bdb6…

MALICIOUS

PDF

73.2 KB Created: 2021-09-13 11:36:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 1c31175197088fc8784ea08a7dc25bb1 SHA-1: b8a4dfaffbf511b09c2c1858b4c9a2009d94e1fe SHA-256: 35530f39bcf5bdb60bc86abc571a085272b156f357c726880d615ca6eb09c149
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and a large number of external links, many pointing to PDF files on various domains, suggests a phishing or malware distribution scheme. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, indicating a tactic to obscure malicious links within a large number of seemingly unrelated domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://terhautz.com/upload_files/files/67293827595.pdf In PDF document text
    • https://habibitoursegypt.com/ckfinder/userfiles/files/84709842561.pdfIn PDF document text
    • http://montoaneli.com/ckfinder/files/3760101058.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fb37e5c193---18582373418.pdfIn PDF document text
    • https://easternresources.net/ckfinder/userfiles/files/21547591064.pdfIn PDF document text
    • http://fuzoku-kyujin.jp/ckfinder/userfiles/files/82425260058.pdfIn PDF document text
    • http://bygreenpure.com/userfiles/file/xibejinun.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/3e9peg7ov9t760lc9jab077i93/41703794996.pdfIn PDF document text
    • https://bodykneadstherapy.com.au/ckfinder/userfiles/files/risupinox.pdfIn PDF document text
    • http://stimatacasa.eu/userfiles/files/54510943527.pdfIn PDF document text
    • http://deepakbatteries.com/uploads/file/3872788391.pdfIn PDF document text
    • https://uleshuzatabc.hu/files/file/52837331823.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613b55fb74311---86527680302.pdfIn PDF document text
    • https://jahanchart.ir/data/files/file/zanogekajubikazo.pdfIn PDF document text
    • https://chingchia.com/uploads/files/202109020917111646.pdfIn PDF document text
    • http://helder-effect.nl/userfiles/file/gugizurogexakipewi.pdfIn PDF document text
    • http://rudolphi.nu/userfiles/file/79122035018.pdfIn PDF document text
    • http://totoumi.jp/upload/file/pofiso.pdfIn PDF document text
    • http://tonioloclaudio.it/userfiles/files/56367594323.pdfIn PDF document text
    • https://lanjutpt1.com/contents/files/80185531214.pdfIn PDF document text
    • http://actinq.nl/upload/file/jonarowaxelobabukowavozor.pdfIn PDF document text
    • http://sun-tes.ru/files/file/sevev.pdfIn PDF document text
    • https://upbfassadenbau.com/upload/file/96961067832.pdfIn PDF document text
    • http://to-kajihan.net/js/upload/files/70815442510.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=mathematical+proofs+chartrand+pdfPDF link annotation
    • http://e1pl2.nazwa.pl/busy/fotki/file/pofuwifav.pdfIn PDF document text
    • 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_off0000b653.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB653 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE6A 10880 bytes
SHA-256: 495fbc7b6abc20a55127bc7fac6b99f363b93a889a849cd982a2ec8b6cb1542d
font_02_sfnt_off0000e758.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE758 18664 bytes
SHA-256: 4269ae3f8ca9d9836162e9a04740d94dc1a70efcfa033963b755e3e59d058df5