Malicious PDF — malware analysis report

Static analysis result for SHA-256 a38e4e834b36cc65…

MALICIOUS

PDF

70.6 KB Created: 2021-09-23 06:55:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: a4a685b2721efc56e4af21ccfe504609 SHA-1: bb121118877b12efd3d6e23aff8e4bbe3b82c14e SHA-256: a38e4e834b36cc65c869d689ecb1d23ed66a63803905e492f80579eb065b1f3f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URIs suggest it's designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://sayarbobinaj.com/file/dumebunesuzorolosujigu.pdf In PDF document text
    • https://truongthanhco.vn/webroot/img/files/77027281261.pdfIn PDF document text
    • http://klubbelgickychobrov.sk/editor_uploads/files/59690571808.pdfIn PDF document text
    • http://flairpens.ru/uploads/files/66175985617.pdfIn PDF document text
    • https://wendi101.com/userfiles/file/41975708630.pdfIn PDF document text
    • https://facades-et-traditions.com/actualites/file/wejawinemulaboj.pdfIn PDF document text
    • http://alnadaoil.com/userfiles/file/73014460634.pdfIn PDF document text
    • http://pushgroup.lv/userfiles/files/88117389849.pdfIn PDF document text
    • http://bytip.net/filespath/files/20210910123127.pdfIn PDF document text
    • http://blekinge.boj.se/uploads/userfiles/files/zitivelijin.pdfIn PDF document text
    • http://werder-ritter.de/UserFiles/File/samosisokakozev.pdfIn PDF document text
    • https://cribpointonline.org/cribpointonline/userimages/file/75667973754.pdfIn PDF document text
    • https://rieker-consulting.eu/files/file/54610736463.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/letosofanilokupoja.pdfIn PDF document text
    • https://jnvhardoi.org/ckfinder/userfiles/files/buzupirefoxawadimaka.pdfIn PDF document text
    • http://bscsaoner.in/ckfinder/userfiles/files/12816004159.pdfIn PDF document text
    • http://elandtour.com/FileData/ckfinder/files/20210919_0E0F77ECCB15E378.pdfIn PDF document text
    • https://deltagroup.bg/uploads/file/26080728614.pdfIn PDF document text
    • http://n2nnetworks.com/files/others/betigitob.pdfIn PDF document text
    • https://envida-nieuws.nl/bsb_website/upload_fck/file/90548983786.pdfIn PDF document text
    • http://cp-tournament.org/ckfinder/userfiles/files/44629054380.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/16134fc980469c---77151723031.pdfIn PDF document text
    • http://hwangtosidae.com/userData/ebizro_board/file/fifegenagipiwadawowixog.pdfIn PDF document text
    • http://japanbizkorea.com/userData/ebizro_board/file/favetubazavikoba.pdfIn PDF document text
    • http://jingkangchem.com/upload/files/pokunekelugok.pdfIn PDF document text
    • http://hanabi-la.com/uploads/files/6090723186.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=after+2+pdfPDF 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_off0000b39f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB39F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cbb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBB5 9900 bytes
SHA-256: 27300fbc1ff90bfbf4a10eb348a20699500f23745ccf7734a243103024eac660
font_02_sfnt_off0000e1b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1B7 16624 bytes
SHA-256: f439008e88a1f3035e0535b2e033288309f8caf889d741a1c4334d7029616905