Malicious PDF — malware analysis report

Static analysis result for SHA-256 c28339ea14fdb9c1…

MALICIOUS

PDF

82.9 KB Created: 2021-09-18 19:19:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 239b77d1561ded1316f2ad358fe84f75 SHA-1: 21502eabbd685c0ebbaec2962ea159e5fd34a572 SHA-256: c28339ea14fdb9c1aa8fbd344a9fb100a23ec10d84730fc6e5aae6a2d93c3c32
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains numerous embedded URLs, many pointing to disposable domains, suggesting a link farm or redirection mechanism. The PDF structure and embedded content are heavily obfuscated, but the presence of external links and the high ML score strongly suggest malicious intent, likely to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://aelma.com/sites/default/userfiles/file/21147052851.pdf In PDF document text
    • http://xn--3bsx3iw22bmot.com/filespath/files/20210901021452.pdfIn PDF document text
    • https://santaclara.com/wysiwygfiles/file/xixoxadadogivugozunupave.pdfIn PDF document text
    • http://bud-med.eu/userfiles/file/60410760740.pdfIn PDF document text
    • http://szentistvanpatika.hu/upload/file/porixesup.pdfIn PDF document text
    • http://jpind.pl/userfiles/file/83879932174.pdfIn PDF document text
    • http://fundacjahfg.pl/upload/file/sinemoxoz.pdfIn PDF document text
    • http://pk.mo/userfiles/file/dazokufomesiveje.pdfIn PDF document text
    • http://abbuffalowings.com/uploads/files/16698646458.pdfIn PDF document text
    • http://hoteldanang.com/uploads/images/files/jinimepaxinapu.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613379ba89abb---kofexukeguj.pdfIn PDF document text
    • https://namphuctourist.com/userfiles/file/vikowibegotuta.pdfIn PDF document text
    • http://goldendazzle.com/upload/quangtri/files/39625015598.pdfIn PDF document text
    • https://cpsguffanti.it/uploads/file/dopesanerifiwefajirakipi.pdfIn PDF document text
    • http://bacsiha.com/public/ckfinder/userfiles/files/tatelinewaxi.pdfIn PDF document text
    • http://tourister.kr/userfiles/file/82462526032.pdfIn PDF document text
    • https://chorland-dining.com/webroot/editor-uploads/files/jusapenebubipefusazaweba.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/16139f7d09e21b---kekelikig.pdfIn PDF document text
    • https://portalkucharski.pl/app/webroot/media/files/56964206585.pdfIn PDF document text
    • http://kodemari.info/data/files/97602314084.pdfIn PDF document text
    • https://gkia.org/kingkong/userfiles/files/55385059991.pdfIn PDF document text
    • https://lexconsulting.ro/webroot/files/media/jesumisukasu.pdfIn PDF document text
    • http://nsfeed.com/_UploadFile/Images/file/6780427616.pdfIn PDF document text
    • https://batdongsandothanh.vn/luutru/files/xasore.pdfIn PDF document text
    • https://pima-alarms.net/slicice/file/39614871756.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=best+free+android+video+playerPDF 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_off0000e01e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE01E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f830.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF830 17616 bytes
SHA-256: 6aa6a22205c8e371fd9afeb75f490f9094748a969f075280b80d7f4b108dca9e
font_02_sfnt_off0001256d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1256D 10724 bytes
SHA-256: 18a23789c52bf6e47754cfc73da2aca39e4ae5cedd5d5b230e6b547565b472f3