Malicious PDF — malware analysis report

Static analysis result for SHA-256 a171cde6346ec4ec…

MALICIOUS

PDF

74.6 KB Created: 2021-09-15 10:21:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f522525d17b5a4959a71aa301309444b SHA-1: 253b40f29a3846c1e9ae630e3c1fb8d58fbeb589 SHA-256: a171cde6346ec4ecf6e8162b103dc8f676c18cc323b1c1d23921eb9039becafb
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was flagged by a machine learning classifier and ClamAV as malicious, with specific detections for PDF phishing and trojan activity. The presence of numerous external URIs, many hosted on disposable domains and configured as link farms, strongly suggests a phishing or malware distribution scheme. The heuristic 'SE_DOWNLOAD_BUTTON' further indicates a lure to encourage user interaction for downloading content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 6

  • 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.
  • 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://dwornawodzie.pl/userfiles/file/patifole.pdf In PDF document text
    • http://chiaranannini.com/userfiles/files/3172973686.pdfIn PDF document text
    • http://kowalstwwo.pl/public/cms/images/file/49398072267.pdfIn PDF document text
    • http://mariancozma.com/_user/file/69736055763.pdfIn PDF document text
    • http://thuexe7cho.vn/upload/files/7191874024.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/70339221129.pdfIn PDF document text
    • http://casaperferiesantamariagoretti.com/writable/public/userfiles/file/72923159559.pdfIn PDF document text
    • http://chothuexeninhbinh.net/data/dulieu/files/66773354776.pdfIn PDF document text
    • http://veterky.ru/ckfinder/userfiles/files/15103249582.pdfIn PDF document text
    • http://mitcostruttori.it/userfiles/files/37981299197.pdfIn PDF document text
    • http://impex-italia.it/userfiles/files/84375814717.pdfIn PDF document text
    • http://ohmytour.kr/FileData/ckfinder/files/20210902_BE29725C4C13B930.pdfIn PDF document text
    • http://starroadchina.com/userfiles/file/77580569030.pdfIn PDF document text
    • https://banerjeetourspecial.in/ckfinder/userfiles/files/80116551751.pdfIn PDF document text
    • http://tottazo.com/userfiles/file/sepodajigajitexasemifo.pdfIn PDF document text
    • https://triatlonshop.cz/userfiles/file/14852423331.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/161331a8409377---87179729973.pdfIn PDF document text
    • https://securitydm.com/slicice/file/xodedixogisixezavizo.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/9a7d476c1b336177859570f731285cfc/guzimirepumoninivatopan.pdfIn PDF document text
    • http://sieuthibds.net/images/files/87656641084.pdfIn PDF document text
    • https://ags-car.60km.com/upload/files/34953488218.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613590fac5569---7060938217.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=papa%27s+when+sundaes+attackPDF 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_off0000bcab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCAB 18388 bytes
SHA-256: 495111ed7c603805071b2387385816ffe4d8227e91a0529d120714450546e13c
font_01_sfnt_off0000ece8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECE8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000104ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104FF 10568 bytes
SHA-256: e43bcf8319ce7baf0d96140101d804099cd415eab9ed7f1d9b12da230329f34d