Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb1eac4b5faabf70…

MALICIOUS

PDF

82.6 KB Created: 2021-09-05 05:00:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 69bffa11ea6a2bcef73ac096969d7de5 SHA-1: b7b8913c31e38f28dd014501d89a6291771ced0c SHA-256: cb1eac4b5faabf706cba83168a814d3862d9bd3113e7580ba48a221a43fd7359
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm or SEO manipulation tactic. The document body is unreadable, but the heuristics indicate a focus on external URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://microcement.ua/userfiles/file/91865475697.pdf In PDF document text
    • http://vkts.se/userfiles/file/60520457698.pdfIn PDF document text
    • http://s4l.vn/storage/ckfinder/files/kilofize.pdfIn PDF document text
    • http://newbusan.net/FileData/ckfinder/files/20210809_BCE9B6DB6114F22B.pdfIn PDF document text
    • http://phongthuydotho.vn/upload/files/6054458578.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16073ae26b63a1---35374936396.pdfIn PDF document text
    • http://domoticasociale.it/immaginiNewsletter/file/fijozorikenanu.pdfIn PDF document text
    • https://wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/wiriv.pdfIn PDF document text
    • https://farstaslottsvik.nu/anvandarbilder/153/files/fakepepazolowulexo.pdfIn PDF document text
    • http://romanakladatelstvi.cz/userfiles/file/36437606385.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1611a1d9336588---14694539418.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/7d5f3953d5b1a27d250db5f039cfb9b2/dalolotenojulafapa.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/nujeguf.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a83905ecf6e---midobal.pdfIn PDF document text
    • https://gullyracing.it/admin/ckfinder/userfiles/files/67329753237.pdfIn PDF document text
    • http://creaorganization.com/depo/sayfaresim/file/zubodogamafezudunajo.pdfIn PDF document text
    • http://krevue.cz/UserFiles/File/37235329964.pdfIn PDF document text
    • https://cuisinescartier.ca/upload/editor/file/78248838426.pdfIn PDF document text
    • https://kit-veron.my/ckfinder/userfiles/files/povebifo.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/sirinifinuzakozob.pdfIn PDF document text
    • http://dastone.ru/userfiles/file/tenamosuwele.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/160f4699ae1acd---mejarezat.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=950h+wheel+loader+parts+manualPDF 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_off0000d7c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7C0 19436 bytes
SHA-256: 4068870949bc200f00765abab558f202f7777af64a0e6213afb2f1580b16a915
font_01_sfnt_off00010acc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ACC 11076 bytes
SHA-256: fa2e73ae55839660d0052d4d18e12b0a5d97eb721b0ba3449f90e4bde3631844
font_02_sfnt_off0001248d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1248D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1