Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4639cf77b48c3c0…

MALICIOUS

PDF

78.4 KB Created: 2021-07-03 04:53:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e678ebcd122ec8cd657abf7557b5b155 SHA-1: d2a5f40ddf305b40496424c0258423e8ee7947c7 SHA-256: b4639cf77b48c3c0bbbc912cdc14459637fd3673f8288bcfe64f8695544a8568
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript and a large number of external URIs, many of which point to compromised WordPress upload directories or disposable hosting. The embedded JavaScript likely facilitates the redirection to these malicious links, aiming to trick users into downloading further malware or submitting sensitive information. The ClamAV detection and ML classifier strongly indicate malicious intent, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 https://satuldelut.ro/ckfinder/userfiles/files/temigawuzejawozilojufu.pdf
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2d982f1dc---56387404416.pdf
    • http://ttlh.vn/storage/ckfinder/files/92724053957.pdf
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/87f9f0322bf6275ea8fc07d9e8d63873/17969197821.pdf
    • http://qianxish.com/ckfind_image/files/81045770396.pdf
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/q68rdgtb957sikf6hcnbp95vkr/topunakaruxufixaw.pdf
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/3fcb5cf51692569ef24d1a6c5a70cd62/tagolezolij.pdf
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/da9c143bbd6e4642a6ceadbce1eaa137/kefivoguxuxewezisat.pdf
    • http://hysansam.com/fckeditor/userfiles/image/kovigebevokoxifa.pdf
    • https://vigiweb.cl/dinamicos/files/file/45793357980.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a910b4dd0be---54745959961.pdf
    • https://beytarimcilik.com/admin/editor_resim/file/38965339976.pdf
    • https://sportli.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1608ca66fcd3e4---desuwuxubebapogerow.pdf
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/4515f4225dc49f0aab85b0d4d8f4efb5/48430011103.pdf
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c3732d517bd---33061606288.pdf
    • http://capitaloffice.pl/fotki/file/30768854606.pdf
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/85b2583ba6209e648f6d8759260c44a4/74765902072.pdf
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1607a96b4b09be---vitekogoxetotamalali.pdf
    • https://comobrew.com/newsite/images/user_uploads/file/51967689001.pdf
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a33d80e961e---12866101601.pdf
    • https://uetty.xyz/js/ckfinder/userfiles/files/48821719444.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=harrison+twp+library
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ce97.bin
baf182328853beaf4fdb0517c8974254c2e77311c2041e7d446607077278772e
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE97 18108 bytes
font_01_sfnt_off0000fd2e.bin
39d36d0e75174d55cfbd9b2f4af43a7d7416a33e9483fee17d91436b78fa5e9f
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD2E 10444 bytes
font_02_sfnt_off000114c5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x114C5 16792 bytes