Malicious PDF — malware analysis report

Static analysis result for SHA-256 3987848fbe6de94e…

MALICIOUS

PDF

84.7 KB Created: 2021-09-21 14:03:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 10ad64fb25a6723bce54480007954986 SHA-1: 8206c9e9edcc993b61c9f4afa72f9fdecb2f7ae5 SHA-256: 3987848fbe6de94e736ed77f1c9640b29f7058da332e452d6bc13a0291981e16
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The PDF contains numerous embedded links, many of which are hosted on disposable domains and appear to be part of a link farm, suggesting a phishing or malware distribution scheme. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing lure designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • 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.
  • 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://jr.ac.th/ckfinder/userfiles/files/53690491855.pdf
    • http://orgue-chantepie.info/FCKeditor/upload/file/mupazojutedagulinejagikab.pdf
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613e9fbf59015---jimobifoloduti.pdf
    • http://boschvietnam.com/files/usersfiles/files/dopupuwaxuxoxu.pdf
    • https://khotelmarket.com/FileData/ckfinder/files/20210906_40F78E80664630C7.pdf
    • https://minhvuongthuphap.com/upload/ck/files/pagiledusurimuxi.pdf
    • https://299-45.com/CKEdit/upload/files/lijozi.pdf
    • http://gourmethousemacau.com/UploadFilesfile///jumumo.pdf
    • http://ministerium.pt/files/jefexi.pdf
    • http://aerotechgroup.ru/img/outer/files/rozev.pdf
    • http://aylincinarli.com/fckfiles/file/dizipikexelabololadazojaw.pdf
    • http://hoaiduc.edu.vn/ckfinder/userfiles/files/95681048462.pdf
    • http://aumnat2car.com/ckfinder/core/connector/php/upload/files/79478625796.pdf
    • http://teacherandtraining.com/coj_u/KK/userfiles/files/gixalijidoba.pdf
    • http://szm.hu/userfiles/file/29433732878.pdf
    • http://chatyzvule.cz/uploads/pufewuretejigepoda.pdf
    • https://christianbelieversmatrimony.com/web/christiansbelieversmatrimony/photos/ckeditor/files/fuminujuvenil.pdf
    • http://riverside-plaza.com/upload/userfile/files/kepiditodoguruvuli.pdf
    • https://damiel.eu/userfiles/file/fupagul.pdf
    • http://cdn.eagle.mn/uploads/userfiles/files/22412449351.pdf
    • http://abovomedia.hu/_user/file/semomepotipakosikupufonig.pdf
    • http://yevres.fr/ckfinder/userfiles/files/79867487409.pdf
    • https://ctners.com/ckfinder/userfiles/files/mesakuraxerusetiluzojan.pdf
    • http://brainbond.ro/userfiles/file/74683300610.pdf
    • http://wirtrauenuns.ch/images/file/70562301061.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=download+bob+the+robber+5+mod+apk
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea01.bin
6b5d8b5d7925808e1cdf66d5048c650c0b98a73664f04a3ebd770c6445b8b44c
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA01 10852 bytes
font_01_sfnt_off000102be.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x102BE 16792 bytes
font_02_sfnt_off00011ad0.bin
7734940af09f1409f045943b7eaec0afbc63202c9155975dd23dbdef215eac6d
pdf-font-stream PDF embedded font (sfnt) at offset 0x11AD0 17476 bytes