Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f1836afa97dfa4f…

MALICIOUS

PDF

94.6 KB Created: 2021-09-17 13:06:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: f8341cd023ef81680b188d0d67fbfa55 SHA-1: be63260ab1aed2ffe566bcf59d51014a35713334 SHA-256: 4f1836afa97dfa4fae117e009347fa7b73ade5129ed660d0aa1bc4a0712897b1
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, with a specific heuristic identifying it as a link farm on disposable hosting. The presence of external URIs suggests an attempt to redirect users to potentially harmful sites for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://archism.ru/uplcv?utm_term=wonder+woman+84+online+free PDF link annotation
    • http://huarui-bio.com/upload/files/67981029508.pdfIn PDF document text
    • http://zechnerbau.at/images/content/files/vorozotizewoju.pdfIn PDF document text
    • http://esangsok.com/upfile/files/bulizopurokirerefikega.pdfIn PDF document text
    • http://synagoge-stommeln.de/ckfinder/userfiles/files/zivodosodug.pdfIn PDF document text
    • https://robindayne.com/ckfinder/userfiles/files/42957406248.pdfIn PDF document text
    • https://cottingham-group.com/cufiles/files/71257079967.pdfIn PDF document text
    • https://www.wizzfizz.com.au/application/third_party/ckfinder/userfiles/files/dunipekumidurobuvalax.pdfIn PDF document text
    • https://eghamatsafar.ir/basefile/eghamatsafar/files/28545249794.pdfIn PDF document text
    • http://autolavaggiocraparotta.it/userfiles/files/xaronu.pdfIn PDF document text
    • http://elandtour.com/FileData/ckfinder/files/20210914_02817E0E1F29E3CA.pdfIn PDF document text
    • https://istanajpdua.com/contents/files/rusasagijobezurifaguroma.pdfIn PDF document text
    • http://eamenfaraz.com/cache/fck_files/file/senonakuwiwo.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613290401ab6c---74749378268.pdfIn PDF document text
    • http://hcbarrett.com/user_area/file/21150679696.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16131cd08b6dfd---19597752627.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/fewipalanimoralugobabavi.pdfIn PDF document text
    • https://chungcungoaigiao.vnpec.xyz/uploads/files/65319973511.pdfIn PDF document text
    • https://ncvpte.in/userfiles/file/xuwijadovimerot.pdfIn PDF document text
    • http://praguetransfer.com/files/file/59789822251.pdfIn PDF document text
    • https://techinnsrl.com/writable/public/userfiles/file/86841575752.pdfIn PDF document text
    • http://daindnc.com/fckeditor/userfiles/file/48938267570.pdfIn PDF document text
    • http://dermatologomiguelgallego.com/miguel/fck/file/fugixikofeki.pdfIn PDF document text
    • http://netflor.pl/upload/File/tozelifanututipe.pdfIn PDF document text
    • https://gameclub.by/uploads/files/xemila.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_off00010963.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10963 10616 bytes
SHA-256: efe81656ee8f64f53c442e3d1e7ba0dfccf31e671c3dc1fd965ff2c8f1677251
font_01_sfnt_off000121aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121AA 19564 bytes
SHA-256: 1e757a528f7650655efd263aa4dfc167e1727021974797ad1239a11b2b12a9d4
font_02_sfnt_off0001549f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1549F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1