Malicious PDF — malware analysis report

Static analysis result for SHA-256 b44d3828a4410f08…

MALICIOUS

PDF

81.1 KB Created: 2021-09-13 14:46:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d7de546257a23c6fa77057b63102a9be SHA-1: 22406e70fb5a7e91c2e4018de2f974522378fab6 SHA-256: b44d3828a4410f088d75482a389a3329e89d87530eab2fb983f4df39cccee952
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URLs, with one heuristic specifically identifying it as a link farm on disposable hosting, suggesting a phishing or redirection scheme. While no scripts were explicitly extracted, the PDF structure and numerous embedded URLs point towards an attack pattern involving directing users to potentially harmful external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://edinburghpools.com/contents/files/bokomawiwosefigenoguxuja.pdf In PDF document text
    • http://hopkim.vn/upload/files/74516325131.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/3fe83633e8ecf8076a3f58bcc136b1ce/nevavuje.pdfIn PDF document text
    • https://yennenga.org/business_school/uploads/file/tomipifidusipotutafe.pdfIn PDF document text
    • https://www.huaikrachaohospital.go.th/assets/global/lib/ckfinder/userfiles/files/38383419891.pdfIn PDF document text
    • https://takipcisec.com/calisma2/files/uploads/tewusepoboj.pdfIn PDF document text
    • https://selispin.com/calisma2/files/uploads/xatosometikugodobik.pdfIn PDF document text
    • http://exima.kr/userData/board/file/88906909958.pdfIn PDF document text
    • http://transchem-tech.com/Uploadfiles/files/25117283976.pdfIn PDF document text
    • http://www.rpv-drachten.nl/files/file/22667453761.pdfIn PDF document text
    • http://cambresisemploi.fr/ckfinder/userfiles/files/72774308067.pdfIn PDF document text
    • http://abaj.cz/UserFiles/File/lojevuwajoz.pdfIn PDF document text
    • http://eszixv.hu/ckfinder/userfiles/files/xegebisudedokorale.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f22f2c2a0a---wunixodimaniporol.pdfIn PDF document text
    • http://benly-carson.com/product/files/wikimotapopuziluv.pdfIn PDF document text
    • http://glampingcaravan.com/userfiles/file/20210913080735.pdfIn PDF document text
    • http://wabasnb.com/files/fckeditor/file/432546158613c5c9a30509.pdfIn PDF document text
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/tozarimanobuvamogexi.pdfIn PDF document text
    • http://hotelrefah4ter.ir/basefile/hotelrefah4terir/files/mepomelazawebe.pdfIn PDF document text
    • http://hotelgiottotorino.com/userfiles/files/2134765673.pdfIn PDF document text
    • http://xnucleus.com/members/member_images/files/80024170556.pdfIn PDF document text
    • http://homokkepek.hu/editor_up/91176105033.pdfIn PDF document text
    • https://efsanepin.com/calisma2/files/uploads/30867873084.pdfIn PDF document text
    • http://brmxn.com/userfiles/file/20210913182006_lnajxp.pdfIn PDF document text
    • http://leinerpakgelatine.com/survey/userfiles/files/kumemenov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=call+to+bluetooth+apkPDF 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_off0000d9c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9C9 10248 bytes
SHA-256: e02042ab73dde642457b88c62195068463c15ee7124b4c7339104708d839f98f
font_01_sfnt_off0000f0c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000108d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108D8 17728 bytes
SHA-256: b49564444e909ed8d9e603009fb0e095af910a6615d92e6cc5ef73c6db1ae039