Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb891bc5c4304eca…

MALICIOUS

PDF

92.4 KB Created: 2021-03-31 05:03:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: e4e97e3ef3a6fab072524888ac9bc016 SHA-1: 984af2368ce8f34ad2ab8b74288837a4ab156d2f SHA-256: cb891bc5c4304eca7c25b44d5a5617f70daa8c7defa3ba9a149087f180160304
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://baarspo.ru/award?keyword=cg+police+def+result+2020+pdf PDF link annotation
    • http://tujukesabegakom.mygamesonline.org/exploring_child_adolescent_development_berk.pdfIn PDF document text
    • http://goxopisejeza.22web.org/physics_solution_calculator.pdfIn PDF document text
    • https://nojefawagalubab.weebly.com/uploads/1/3/4/2/134266261/a1c01a.pdfIn PDF document text
    • http://wokanetavim.iblogger.org/need_of_working_capital_management.pdfIn PDF document text
    • http://dawavuwera.22web.org/647020020.pdfIn PDF document text
    • http://gefosezidubajoz.scienceontheweb.net/fikafelifina.pdfIn PDF document text
    • http://fagogit.sportsontheweb.net/ahle_hadees_urdu_free_download.pdfIn PDF document text
    • http://tapozifokun.mywebcommunity.org/gumuxaxafexa.pdfIn PDF document text
    • https://bizalaso.weebly.com/uploads/1/3/4/4/134443832/4139234.pdfIn PDF document text
    • https://rimemukevip.weebly.com/uploads/1/3/4/3/134318995/6377322.pdfIn PDF document text
    • http://momarivido.mypressonline.com/26085585830.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fedorahosted.org/lohitIn PDF document text
    • http://kofaxafogi.myartsonline.com/78728148452.pdfIn PDF document text
    • https://s3.amazonaws.com/miwolezedubujoz/android_studio_install_gradle_3._3.pdfIn PDF document text
    • http://bitenozof.atwebpages.com/30652232115.pdfIn PDF document text
    • https://s3.amazonaws.com/falevi/asurion_affidavit_att.pdfIn PDF document text
    • https://s3.amazonaws.com/rokuwapesu/google_chrome_android_tv_apk_mirror.pdfIn PDF document text
    • http://ranitirunom.myartsonline.com/vokugevusazapebugox.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://scripts.sil.org/OFLIn PDF document text
    • http://www.geocities.com/mitra_anirban/hobbies.htmGNUIn PDF document text
    • http://www.gnu.org/copyleft/gpl.htmRegularIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f04c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF04C 5292 bytes
SHA-256: aef063b820b7142a528c3466aa729c7ef061da0e5d6addecb898efe87102f308
font_01_sfnt_off00010263.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10263 3720 bytes
SHA-256: d0c9e33916e9e64e42e31bcf0d345f6c2fcd41735b1a34df0119bd0eb1094281
font_02_sfnt_off00010dc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DC7 10944 bytes
SHA-256: 9b2af37bb82f0f26282fd12425ce195d284bd80959b6eace0393b64fbce5bc71
font_03_sfnt_off0001334d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1334D 16644 bytes
SHA-256: 4a0bc85cdae78baeabf88d24b2f7f04949283fcf7777bacba115074e665ce618