Malicious PDF — malware analysis report

Static analysis result for SHA-256 f7d5f2ce65056960…

MALICIOUS

PDF

77.9 KB Created: 2021-04-22 00:06:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: ae8d003f91e608228284387427151f8c SHA-1: c7abaa36ddb2d9efd8924cb427d258ac0b9af258 SHA-256: f7d5f2ce650569606997f09120cbce31ee34ebb0b44cc35c75bc62b8804d9897
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was identified as malicious by both ClamAV and an ML classifier. It functions as a link farm, containing numerous external URLs, with a primary suspicious URL being https://jacksth.ru/strik. The PDF's structure and the presence of multiple links suggest an attempt to direct users to potentially malicious content or phishing sites, aligning with the characteristics of a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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.
  • 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://jacksth.ru/strik?utm_term=cuanto+es+un+decimetro+en+centimetros PDF link annotation
    • https://cdn.sqhk.co/wizokawoxo/jjqtn0V/94872394544.pdfIn PDF document text
    • https://cdn.sqhk.co/neliwuwo/2ibebic/17123769233.pdfIn PDF document text
    • https://cdn.sqhk.co/mujowofapubi/Mujigec/96137101117.pdfIn PDF document text
    • https://cdn.sqhk.co/doginifa/ajdijkf/the_political_machine_2020_ideology.pdfIn PDF document text
    • https://cdn.sqhk.co/fuwasokeg/Giehjsw/stop_crawling_robots._txt.pdfIn PDF document text
    • http://dovulup.iblogger.org/jevafamenoxofovujog.pdfIn PDF document text
    • https://cdn.sqhk.co/memenewo/gf1hdBq/fosatokofedekavixaziwenu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://a40b6db0-1679-4e03-879f-ac5827b9aa7d.filesusr.com/ugd/dba42a_faeb221cf341433b82b8ee01dbd495cc.pdf?index=trueIn PDF document text
    • https://156bb51f-0b62-477f-88ca-8620af00812b.filesusr.com/ugd/e3ff21_d0a2c346961043d48d30cea8262cf8ed.pdf?index=trueIn PDF document text
    • https://3568ea06-17fa-4787-91ae-86b9aa918cbd.filesusr.com/ugd/8ade13_6f95059eaf414a9987525b97a4ad32df.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/golepe/tamil_songs_ringtones_free_for_iphone.pdfIn PDF document text
    • https://s3.amazonaws.com/bidemewufa/whatsapp_for_android_tablet_free_apk.pdfIn PDF document text
    • https://eee5dff6-7331-416e-acdf-593d0c386862.filesusr.com/ugd/21e9e0_674b05e9b7da45ec9a81f108c7ba75ec.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kovibu/start_your_own_blog_ukulele.pdfIn PDF document text
    • https://s3.amazonaws.com/sixolose/what_type_of_oil_for_generac_gp5500.pdfIn PDF document text
    • https://7a69a04d-b0b3-478e-a927-895b34d3dd44.filesusr.com/ugd/159848_f5b894dda2b743128f8ed05693e13498.pdf?index=trueIn PDF document text
    • https://cc6d8859-fc08-4100-a073-55b48c5addfc.filesusr.com/ugd/238140_6c9956bae66f4072a5c5de0cfbc92247.pdf?index=trueIn PDF document text
    • https://4b4ea461-5266-411b-8735-d5290551f550.filesusr.com/ugd/7fedcf_9a4c2656912f44eda95dbcc483393e45.pdf?index=trueIn PDF document text
    • http://bogurivesinoni.rf.gd/air_cooler_mini_project.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://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_off0000daa2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAA2 4956 bytes
SHA-256: fe6f6dc514fc69588568384abe7115ea1e005d0c1704a6a529a2a4ff015ef9bb
font_01_sfnt_off0000eb64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB64 12044 bytes
SHA-256: 3a70d8e600ab2a9b0ca197b2f34ab67d1cab45fd73f3dbf91cf3f685163e5402
font_02_sfnt_off000112f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112F8 16100 bytes
SHA-256: 9e9cd3e823d2b2c43597f4611ab9b63d40ea3e1a9eeb22e83fdae90966f5e152