Malicious PDF — malware analysis report

Static analysis result for SHA-256 57c71be8d4a643bc…

MALICIOUS

PDF

79.4 KB Created: 2021-09-18 05:33:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9f7d52a72766a5531fb0d85d1d50bee0 SHA-1: 9fec2e4cb561f39c3807d9a7bfac345c269275fc SHA-256: 57c71be8d4a643bc2aa499b8d7d500d196d7af46163ea2d1bd68a727be598ef6
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple embedded URLs and is flagged as a link farm on disposable hosting, indicating a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly suggest malicious intent. The file's structure and embedded links are consistent with a spearphishing attachment used to lure victims to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://crewmak.ru/uplcv?utm_term=font+changer+for+android PDF link annotation
    • http://mgtofubbq.com/uploads/files/zisalilip.pdfIn PDF document text
    • http://emusicmarket.com/upfile/board/files/67356632231.pdfIn PDF document text
    • http://mgtuae.com/uploads/file/96349321225.pdfIn PDF document text
    • https://stollerco.com/testingsites/advantage_aviation/assets/media/file/27824997774.pdfIn PDF document text
    • https://detectagsafety.com/ckfinder/userfiles/files/47312354216.pdfIn PDF document text
    • http://ctyrkolky-gamax.cz/data/dokumenty/51874157428.pdfIn PDF document text
    • http://jinanxintiandi.com/userfiles/files/wagesebiwuguv.pdfIn PDF document text
    • http://thecargonepal.com/userfiles/file/87576851496.pdfIn PDF document text
    • http://dvg.asia/ckfinder/uploadfiles/files/60561984462.pdfIn PDF document text
    • http://dlzhrjd.com/images/uploadfile/files/fewulowoxoxodibaxibefiru.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ed0139f414---safivogonoroxijixafe.pdfIn PDF document text
    • https://childrencareandliteracysociety.org/userfiles/files/1769466214.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614280a9244e1---mibugusezonaxoxuzelo.pdfIn PDF document text
    • https://fobh.net/userfiles/files/vefagetal.pdfIn PDF document text
    • https://caribemed.com/userfiles/file/29642887920.pdfIn PDF document text
    • http://z-him.ru/userfiles/file/pexapufafigurogafo.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16143fe526b151---50043184721.pdfIn PDF document text
    • http://alompar.hu/uploads/content_files/files/lafamozurizum.pdfIn PDF document text
    • http://zgkimsteszew.pl/img/upload/files/41928036565.pdfIn PDF document text
    • http://atlonnuri.org/UpLoadImage/editer/files/34888961561.pdfIn PDF document text
    • https://www.theknowledgeonline.com/files/lib/ckfinder/userfiles/files/riliripo.pdfIn PDF document text
    • http://lpsa.cz/userfiles/file/tokotetuwuze.pdfIn PDF document text
    • http://phaptangpgvn.net/app/webroot/upload/files/pudotabi.pdfIn PDF document text
    • http://benevolo.it/userfiles/files/lopudufebatemufejafiwa.pdfIn PDF document text
    • 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_off0000d45d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD45D 10516 bytes
SHA-256: 245e6b44a3873d5318282b02ab68fd4ed5e8cc5ba71d19ee7d1014152fab95f2
font_01_sfnt_off0000ec09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC09 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001041b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1041B 17212 bytes
SHA-256: daf7da3de957842ff966828b9eaa6c273623fd210171f24d6d9b457b128b92a0