Malicious PDF — malware analysis report

Static analysis result for SHA-256 83e7e79351cc3431…

MALICIOUS

PDF

75.8 KB Created: 2021-09-18 02:09:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 24dea465d3206e4364cd90b931b1732a SHA-1: 1f27dbab04e8fe24d71e0a189b4f516c1caae53e SHA-256: 83e7e79351cc34314e82926db7bb5fb937c0b0abe95909e14f019b21a906589c
156 Risk Score

Malware Insights

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

The PDF document was flagged by ML classifiers and ClamAV as malicious, indicating it likely contains an exploit. Heuristics reveal it functions as a link farm, directing users to various external PDF files hosted on potentially compromised or disposable domains. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM firings strongly suggests an attempt to distribute malicious content or phish users through these linked documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://udmvdpo.ru/images/files/fogisanugenar.pdf In PDF document text
    • https://torbay.ru/images/uploads/file/56346751879.pdfIn PDF document text
    • https://washlounge.in/ckfinder/userfiles/files/nenimaberidomubesupenilu.pdfIn PDF document text
    • http://humansharehouse.com/userData/board/file/wetigorozedikenexonotid.pdfIn PDF document text
    • http://xn----ctbguteehkho5h.xn--p1ai/ckfinder/userfiles/files/liditomilakumarowepobuzug.pdfIn PDF document text
    • http://srcchaika.ru/files/uploads/files/sijuber.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613c36551a7f4---nuwevawo.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ecf7f7acf4---pudevejazugotimev.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/16132b0d2ebfad---faguw.pdfIn PDF document text
    • https://gsacademy.ge/uploads/files/segarozujivosubi.pdfIn PDF document text
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/15483679e14cf13aaaf2efba8f4ab25f/jamosebejimatovomexe.pdfIn PDF document text
    • http://abwingsbuffalo.com/uploads/files/boderorazapamigodaxomon.pdfIn PDF document text
    • https://itscebu.com/upload/file/20210913151423.pdfIn PDF document text
    • http://hglobaltour.com/FileData/ckfinder/files/20210904_D3C42BE67A22BEC0.pdfIn PDF document text
    • http://nawooelcs.com/upload/userfiles/2021/09/files/210905153052.pdfIn PDF document text
    • http://kodemari.info/data/files/nevabifurinuli.pdfIn PDF document text
    • https://sapsda.com/SapmaUserfiles/file/fonefukajefuvobuxuxosiko.pdfIn PDF document text
    • http://eapver.com/upload/ckimg/files/202109170026254189.pdfIn PDF document text
    • https://demo.wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/situpixifijideraxo.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1612f56f550afe---suwewipuwudixiz.pdfIn PDF document text
    • http://aotwresort.info/ckfinder/userfiles/files/norelulipitologejuledupa.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613e6cbabc157---manafebelebezazogoxuv.pdfIn PDF document text
    • http://energo-winstal.pl/userfiles/file/kikolikinokifat.pdfIn PDF document text
    • http://pure-chiral.com/upload/files/74952068414.pdfIn PDF document text
    • https://perfumes.dropship-tracking.com/userfiles/files/sovotoritezoj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=download+hungry+sharkPDF 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_off0000c438.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC438 10600 bytes
SHA-256: 2639e9b4a5470cf52eb173c3d44013769685f9c3f837f25100902596c2aaccb2
font_01_sfnt_off0000dc32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC32 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f444.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF444 17416 bytes
SHA-256: ddc40f21fc6c8bcc86302e454cdd8f3a803042a1aa6376493ec79f25e2bb83a6