Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7bc6430c7e599a3…

MALICIOUS

PDF

69.8 KB Created: 2021-09-26 05:50:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: ab8dd3eb4433b64b588bcf8466411a3e SHA-1: c38b1e5218ecc50e29c87058fda99038bdfec852 SHA-256: a7bc6430c7e599a3d83cd8f212223aadf31c91c9f3c7eaccd0f5075071601a01
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. The heuristic analysis indicates it functions as a link farm, directing users to numerous other PDF files hosted on various domains. While no scripts were explicitly extracted, the nature of PDF exploits often involves embedded JavaScript for malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://baschin-heizung.com/meineBilderAlbertGrundschule/file/5732825357.pdf In PDF document text
    • https://webornate.com/viking1/uploads/files/97044484430.pdfIn PDF document text
    • http://xn--80aantfcaehjbxzf1m.xn--p1ai/userfiles/file/23820879626.pdfIn PDF document text
    • http://cualuoiskydoor.com/webroot/img/files/pujifuvitaduxixerafus.pdfIn PDF document text
    • http://billagelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rupanasumoravusa.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134890d0bed1---2675902442.pdfIn PDF document text
    • http://panhongbo.com/ckfinder/userfiles/site_eachfun_com/files/25665977268.pdfIn PDF document text
    • https://afmiletisim.com/resimler/files/37490601754.pdfIn PDF document text
    • http://sun-green.de/ckfinder/userfiles/files/9938837596.pdfIn PDF document text
    • http://emiem.pl/public/upload/ckfinder/userfiles/files/67412459790.pdfIn PDF document text
    • http://nationshield.ae/userfiles/files/71743578283.pdfIn PDF document text
    • http://toyotarent.hk/FileData/ckfinder/files/20210913_515792520F94A147.pdfIn PDF document text
    • http://jerseybankruptcylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xofidija.pdfIn PDF document text
    • http://gesht.ru/admin/ckfinder/userfiles/files/17402458325.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/13712873503.pdfIn PDF document text
    • https://lescourailleurs.com/upload/editor/file/xoxozelune.pdfIn PDF document text
    • http://speckletrack.com/update/editor/file/95513456197.pdfIn PDF document text
    • http://glamour-nsk.ru/ckfinder/userfiles/files/jitidelumigoziretazefive.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=the+darkest+dungeon+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_off0000ad52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD52 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c564.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC564 16696 bytes
SHA-256: decc3dfa4e377974240f1573d3b96d336530cf25d5f5737b770063d211f76bad
font_02_sfnt_off0000f07e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF07E 10636 bytes
SHA-256: 41e473a40b104d0f019e0c88b6d978bba7144507d539c77a363704d3802ece46