Malicious PDF — malware analysis report

Static analysis result for SHA-256 356663a93d95baab…

MALICIOUS

PDF

82.1 KB Created: 2021-09-23 06:01:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 83a33b6bc74f79f15563ed2f8e2f3829 SHA-1: a15da377160b4a72b520eb303241e7f33a96d9b7 SHA-256: 356663a93d95baab7a794e7b6ce98c8d01a1a04f338fa05b0421c45f0927efe1
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of numerous embedded URLs pointing to various domains, many of which are associated with link farms and disposable hosting, suggests a phishing or SEO manipulation scheme. The document body is heavily obfuscated and unreadable, but the heuristics indicate a link farm strategy, likely to distribute further malicious content or engage in search engine poisoning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://jarosi.hu/files/file/57568013130.pdf In PDF document text
    • http://xn--knstlerische-biografie-arbeit-lbd.ch/userfiles/files/87995585300.pdfIn PDF document text
    • http://centroolosprato.it/userfiles/files/nemokodurexi.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/1a15ef8569431a99c6cae5ad5e582900/89193765364.pdfIn PDF document text
    • https://fresh-cherries.com/ckfinder/userfiles/files/maxusofafateribuwose.pdfIn PDF document text
    • http://tatooazh.ru/files/files/mixupisabo.pdfIn PDF document text
    • https://parc-hotel.info/file/21983141920.pdfIn PDF document text
    • https://medsplus.us/admin/images/file/8945906489.pdfIn PDF document text
    • https://olterus.org/contents/files/26629332072.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/3a1e6cdb003b0094565066adfa20f2d5/papogukuferaferib.pdfIn PDF document text
    • http://www.sandipmallick.com/fckimages/file/9635238841.pdfIn PDF document text
    • https://yauspeshen.com/ckfinder/userfiles/files/81915143332.pdfIn PDF document text
    • http://www.horakgolf.cz/ckfinder/userfiles/files/joponeletapawitivozona.pdfIn PDF document text
    • http://avandcie-automation.com/ckfinder/userfiles/files/34783995480.pdfIn PDF document text
    • http://afslab.asia/upload/files/puziwu.pdfIn PDF document text
    • https://bk.knu.ac.kr/ckfinder/userfiles/files/7499649377.pdfIn PDF document text
    • http://kerekesvillszer.hu/UserFiles/file/81476809369.pdfIn PDF document text
    • http://siamsankyo.com/Uploads/file/48655558279.pdfIn PDF document text
    • https://sonerofset.com/userfiles/file/tesijaxajefajam.pdfIn PDF document text
    • https://traiteur-troyes-mariage-buffet-aube-10.blaisot-traiteur.fr/ckfinder/userfiles/files/jonidubikiwudarul.pdfIn PDF document text
    • https://dzido.pl/userfiles/file/81212753706.pdfIn PDF document text
    • http://appinaris.net/ckfinder/userfiles/publics/files/79143880159.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=ghd+sports+latest+version+downloadPDF 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_off0000dcf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCF4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f506.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF506 17388 bytes
SHA-256: 46ebecf57ed1c9c97556f3dbd79558d4119bad3b1403059a320adb2e8b178890
font_02_sfnt_off000121fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121FE 10680 bytes
SHA-256: 7ed2099c38a154afa42fa7f32436070f9e13cd7611828a2eb303f6870b80e10c