Malicious PDF — malware analysis report

Static analysis result for SHA-256 5461ecb1475f5e8f…

MALICIOUS

PDF

84.0 KB Created: 2021-09-19 06:54:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 541f6a84f2897a4d229471cb9136a21a SHA-1: 8d256f9e74c5b54592ef40623e43e0180e39b6e1 SHA-256: 5461ecb1475f5e8fdb82012a94ea60ff3343b5ef5862c99e23f3ef0ea178e2e7
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.001 PowerShell

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains heuristics indicating it's a link farm and a lure for clipboard command execution, instructing users to paste content into a shell. While no scripts were extracted, the combination of these factors suggests the PDF is designed to facilitate the execution of malicious commands, likely to download and run a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Clipboard command execution lure high SE_CLIPBOARD_COMMAND_LURE
    Document tells the user to copy or paste clipboard content into Run, PowerShell, cmd, or another shell-like execution context
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://nhac.ditimchanly.org/Images_upload/files/22010100066.pdf In PDF document text
    • https://tonerihned.cz/userfiles/file/subizolajisikixidakugepo.pdfIn PDF document text
    • https://ferado.vn/userfiles/file/82947649807.pdfIn PDF document text
    • http://star-transform-moscow.ru/uimg/files/sidatulujixi.pdfIn PDF document text
    • http://belgium-ex.com/images/blog/file/kekekililukusogamituwe.pdfIn PDF document text
    • https://delaneyllc.cfonewsletter.com/ckfinder/userfiles/files/ziketatori.pdfIn PDF document text
    • http://detaycopymatbaa.com/userfiles/file/magalifuxevelogum.pdfIn PDF document text
    • http://herbwaterthailand.com/userfiles/files/24756557472.pdfIn PDF document text
    • http://fitnessklub-impuls.pl/uploads/assets/file/51012717644.pdfIn PDF document text
    • https://tagoproperties.com/ckfinder/userfiles/files/bolewu.pdfIn PDF document text
    • https://szabolcsipeter.com/userfiles/file/pejivuresodixidu.pdfIn PDF document text
    • https://giridhareye.org/ckfinder/userfiles/files/bowovowotifo.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fafd5e5b7e---95858944325.pdfIn PDF document text
    • http://veterky.ru/ckfinder/userfiles/files/25355158933.pdfIn PDF document text
    • http://cgl.lu/userfiles/files/safoguludikopipim.pdfIn PDF document text
    • http://smirna.pl/files/file/78619928863.pdfIn PDF document text
    • https://mbamantra.com/ci/userfiles/files/mulelanuzebexafug.pdfIn PDF document text
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/60225804893.pdfIn PDF document text
    • http://www.prunay-en-yvelines.fr/ckfinder/userfiles/files/folivik.pdfIn PDF document text
    • http://urgentcarepb.net/userfiles/file/16160926213.pdfIn PDF document text
    • https://ldcpc.com/ckfinder/userfiles/files/28998562409.pdfIn PDF document text
    • https://ecohort.info/userfiles/files/88525125170.pdfIn PDF document text
    • http://eyela.kr/uploadfile/fckeditor/file/bomexukajexexe.pdfIn PDF document text
    • http://okna-dvere-online.cz/media/upload/upload/file/18327069743.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=text+edit+apk+downloadPDF 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_off0000e403.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE403 17880 bytes
SHA-256: 3505d593ba9021542f5d254c5b5c3c2d509d08377098fb24f7d19b090349f803
font_01_sfnt_off000112f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112F2 10360 bytes
SHA-256: 49d57b7eda3cade96edc2e4fb46213725c5262faa15665cf4524734d2144da13
font_02_sfnt_off00012a8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A8B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1