Malicious PDF — malware analysis report

Static analysis result for SHA-256 cdc1e8a2dc716e2a…

MALICIOUS

PDF

85.3 KB Created: 2021-09-24 00:02:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 80cb9aba9d79aba4fad828aad96f980a SHA-1: 28a76994833ab6ed96fd069db504b69a646bfb2a SHA-256: cdc1e8a2dc716e2af49ee51be27fa09234b3a1666b41c82862f92870db28c4e1
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and is flagged by ClamAV as a phishing trojan. It also functions as a link farm with numerous external URIs, many pointing to disposable domains, suggesting an attempt to distribute malicious content or phish users. The ML classifier strongly indicates malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://usaoxin.com/userfiles/2021-9/file/74635562912.pdf In PDF document text
    • http://yaan121.com/uploads/files/202109070423554878.pdfIn PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/oj5j3glaervc2uln222leka3g5/98071060062.pdfIn PDF document text
    • https://detskeihriska.eu/ckfinder/userfiles/files/52605352288.pdfIn PDF document text
    • http://offerseir.com/basefile/offerseircom/files/10421126102.pdfIn PDF document text
    • http://chinahongji.com/d/files/zibegowulatu.pdfIn PDF document text
    • http://bioident.pl/photos_fck/file/leletegege.pdfIn PDF document text
    • http://interstroy96.ru/uploads/files/mutaronu.pdfIn PDF document text
    • http://budapesticukraszdak.hu/userfiles/files/75205094190.pdfIn PDF document text
    • http://087334211.kad.tw/kads/ckfinder/userfiles/files/95782249150.pdfIn PDF document text
    • https://liur-krd.ru/userfiles/file/2268234753.pdfIn PDF document text
    • http://mayjack.com/upload/files/72644630980.pdfIn PDF document text
    • http://i-harmonics.com/upload/files/bemuxemeluvugixorunasixa.pdfIn PDF document text
    • https://latrinquette.com/upload/editor/file/katazinimapasedilomi.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/labepogofeneriwikuvopobob.pdfIn PDF document text
    • https://sherwoodchamber.org/ckfinder/userfiles/files/46648573963.pdfIn PDF document text
    • http://abwjefferson.com/uploads/files/nudawejolozuloko.pdfIn PDF document text
    • http://jjw-led.com/userfiles/file/21986444264.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16132af38c249c---7661866908.pdfIn PDF document text
    • https://quanticabtl.com/cms_2018_quantica/sgi_userfiles/userfiles/files/sesigiwelu.pdfIn PDF document text
    • https://www.bankkartya.hu/js/ckfinder/userfiles/files/19656989907.pdfIn PDF document text
    • http://rama-sp.com/rama/webroot/js/ckfinder/userfiles/files/firugafalupedum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=guitar+hero+ps2+androidPDF 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_off0000e13b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE13B 20836 bytes
SHA-256: ff5c6b38090f361e381d8db0798140ca00be4b1925468d7cd298f06652655d6d
font_01_sfnt_off00011784.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11784 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012f9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F9B 10704 bytes
SHA-256: cc9d804eb0812e9efb944e655dbe62c8906d83c00246041f72705ed1846529e8