Malicious PDF — malware analysis report

Static analysis result for SHA-256 c57c9fa2762d284c…

MALICIOUS

PDF

90.5 KB Created: 2021-09-22 20:07:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 0ab213c6588c525b90ae8d346b9a35a0 SHA-1: b447dd1ded8080e8cd5f9e6dd4525997aae3d5dd SHA-256: c57c9fa2762d284cc36522749827e370422592d4502f77f14569bee2e26381c8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, indicating a strong intent to redirect users to potentially harmful content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, suggesting the document is designed to host many links. No scripts were extracted, but the overall structure and heuristics point to a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9924

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://chcial.ru/uplcv?utm_term=pro+android+c%2B%2B+with+the+ndk+pdf PDF link annotation
    • http://hzeiger.com/userfiles/file/mezilulisise.pdfIn PDF document text
    • https://loyalangkorapartment.com/userfiles/file/fezudatutis.pdfIn PDF document text
    • https://mimpidia2.com/contents/files/12783191688.pdfIn PDF document text
    • http://bscartridge.com/pic/38382499051.pdfIn PDF document text
    • http://gldbirdgel.com/user_img/files/82679837985.pdfIn PDF document text
    • http://affectif.ro/data/Image/file/86068525906.pdfIn PDF document text
    • https://pet-fashion.ro/mm/file/13513587460.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/73028348968.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1614a2496daec0---supoxitosunurakudod.pdfIn PDF document text
    • http://rrmkaryacollege.org/rrmkarya/userfiles/file/11411662743.pdfIn PDF document text
    • http://shamayachts.com/upload/file/doxekiduzap.pdfIn PDF document text
    • http://melly-incendie.fr/img_db/wonoz.pdfIn PDF document text
    • http://wiskind.com/filespath/files/20210916030139.pdfIn PDF document text
    • https://spandoekland.nl/userfiles/file/bavajuxafeloxoxabetap.pdfIn PDF document text
    • http://soncongnghiepjotun.com/media/ftp/file/besuxoxavojifigafomo.pdfIn PDF document text
    • https://detectagsafety.com/ckfinder/userfiles/files/wopizobabozunav.pdfIn PDF document text
    • http://svx.su/ffile/file/welinupapexusoxofodenazi.pdfIn PDF document text
    • http://elfuklid.cz/foto/Image/file/6977933931.pdfIn PDF document text
    • http://euroteam.vn/ckfinder/userfiles/files/xugupinazabiritog.pdfIn PDF document text
    • http://www.bluefashion.cz/ckfinder/userfiles/files/43292783122.pdfIn PDF document text
    • http://tauroconsulting.pl/userfiles/file/87485198672.pdfIn PDF document text
    • http://investinwielkopolska.pl/application/lib/ckfinder/userfiles/files/dufinodilugemuduge.pdfIn PDF document text
    • https://tutorsbureau.net/userfiles/file/zajebikurabijakuxawazi.pdfIn PDF document text
    • http://dominant.name/userfiles/file/vekot.pdfIn PDF document text
    • http://ros-grad.ru/fck_editor_files/files/duwitofuveduxututavisofel.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d42d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD42D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ec3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC3E 16756 bytes
SHA-256: 1b2def62ecf4544539e2a1f9ec344c1657f00a2750d36a5eec4db46c099f19a1
font_02_sfnt_off0001044b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1044B 25724 bytes
SHA-256: 0a08bc0f340591f66dd9a050280f51ca692d59ddfea36ab490ab7cea902d7679
font_03_sfnt_off0001436b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1436B 10680 bytes
SHA-256: e1f2f3175898d4cbb269107de8b4d53b4d4a8425af5f6c3d17fb9660b770cf0a