Malicious PDF — malware analysis report

Static analysis result for SHA-256 c23a939caecafda6…

MALICIOUS

PDF

76.1 KB Created: 2021-03-04 10:02:22 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-04
MD5: f5a6e3a64007ad7dd192748fb040bdd6 SHA-1: bbfd5e8acf59577c70539b4fa221aa68cd8bf373 SHA-256: c23a939caecafda6d790962d62f685a88633dbf6d15cc48809a7243f009c4291
226 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

This PDF file was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm designed to direct users to external websites. The document contains numerous embedded URLs, many pointing to disposable domains or link-sharing services, suggesting an attempt to manipulate search engine rankings or distribute phishing content. The presence of 'cmd.pdf' and other suspicious strings within the document text, along with the high number of external links, indicates a likely attempt to exploit vulnerabilities or deliver malicious content via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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://pelibifir.ru/award?keyword=how+to+get+big+chest+and+shoulders PDF link annotation
    • https://cdn.sqhk.co/xopuwomu/cibiiih/33859464527.pdfIn PDF document text
    • http://true-board1.club/77625622498bhre3.pdfIn PDF document text
    • https://rojanebe.weebly.com/uploads/1/3/1/6/131637229/wapolewurarojeg.pdfIn PDF document text
    • http://sugameloxufe.mywebcommunity.org/56340678214.pdfIn PDF document text
    • https://podotetu.weebly.com/uploads/1/3/4/0/134017986/puserogorep.pdfIn PDF document text
    • http://kopogaxepaku.sportsontheweb.net/negipe.pdfIn PDF document text
    • http://pollsexpert.com/how_to_workout_at_planet_fitness_for_freewwvxi.pdfIn PDF document text
    • https://cdn.sqhk.co/nufesewepi/eQrLOha/zekobilivifogewa.pdfIn PDF document text
    • http://govnososal.xyz/57618765708a6snk.pdfIn PDF document text
    • https://cdn.sqhk.co/koditisalupe/9Yhixgc/lucky_hand_pinball_machine.pdfIn PDF document text
    • http://pejelurim.getenjoyment.net/how_to_get_laptop_mac_address_using_cmd.pdfIn PDF document text
    • http://rokuboxajiga.medianewsonline.com/what_is_dominos_vegan_cheese_made_from.pdfIn PDF document text
    • http://najetaxu.mygamesonline.org/final_fantasy_7_remake_xbox_one_release_date.pdfIn macro / runtime command snippet
    • https://cdn.sqhk.co/retagigimusa/gjjaKuT/65095090473.pdfIn PDF document text
    • http://rokuboxajiga.medianewsonline.com/what_is_domiIn macro / runtime command snippet
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.opentle.orgIn 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.gnu.org/licenses/gpl.htmlIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ddc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDC7 5396 bytes
SHA-256: e9b390c8dafe865a82deea64e1ad913b03262f661d247ef88b895ea94ff56298
font_01_sfnt_off0000f022.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF022 6376 bytes
SHA-256: 1a1d7b77a199f01ad5ff3bddf86766436b58ecbaeabb5ed5486034cdf8da2312
font_02_sfnt_off00010109.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10109 9936 bytes
SHA-256: 58b7747c2d6b8aa646792f79634e1fdabc28a8cc08b559081e1cd25b10d61985