Malicious PDF — malware analysis report

Static analysis result for SHA-256 9aa1fc88db6d0a4d…

MALICIOUS

PDF

93.8 KB Created: 2021-03-24 23:25:59 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 24259b6da22b7d2e75c73f0d42902d0d SHA-1: bf5231ed253b390660ba44a61d1357e6afdfa14c SHA-256: 9aa1fc88db6d0a4d206ecf543ed3f32ff2ad2d6746ce4e08cb149e7228afdeff
184 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating it is likely a phishing or trojan distribution attempt. It contains numerous embedded URLs, with at least one pointing to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains text related to 'English story text pdf', likely a lure to disguise the malicious intent of directing users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8566

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://crophysi.ru/award?keyword=english+story+text+pdf In PDF document text
    • https://static.s123-cdn-static.com/uploads/4421330/normal_5fe35e831daec.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4483873/normal_5ffba9fe2a747.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402262/normal_5fd27b2a4ff0d.pdfIn PDF document text
    • http://dfds.in/62367332144s37sv.pdfIn PDF document text
    • https://cdn.sqhk.co/mekoposa/SRdggie/bus_simulator_vietnam_apk_data_free_download.pdfIn PDF document text
    • https://cdn.sqhk.co/gorubabor/jMjgih2/stone_age_boy_book_free_download.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495391/normal_6047beae02aa5.pdfIn PDF document text
    • https://cdn.sqhk.co/ribafesupuro/fZ0jimy/pokozaxogigaxez.pdfIn PDF document text
    • http://vittorguxx.site/what_u_want_in_spanishwfvmi.pdfIn PDF document text
    • http://kyponnik.online/49898312480716of.pdfIn PDF document text
    • http://grantmedica.ru/amnesia_machine_for_pigs_achievements_guideg7xkj.pdfIn PDF document text
    • http://vefaporuzudu.iblogger.org/legiwisetaponepudenil.pdfIn PDF document text
    • http://zoom-omsk.ru/93101087093m9hok.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490736/normal_5fd137aa4402c.pdfIn PDF document text
    • http://logemopi.22web.org/college_volleyball_stat_sheets.pdfIn PDF document text
    • https://cdn.sqhk.co/fuvebopeweb/ifihjbJ/loopback_analytics_glassdoor.pdfIn PDF document text
    • http://valamivu.22web.org/disatawimupusesojejeru.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://wixesazu.epizy.com/abebooks_tom_wolfe_the_right_stuff.pdfIn PDF document text
    • https://9539e3d7-93ad-434a-85ac-22bd9bdb82bb.filesusr.com/ugd/df7b34_1b01a07826e14c8e940afcedfc287de9.pdf?index=trueIn PDF document text
    • https://d62ff7d9-aefc-4ab8-8cdf-af38868aea16.filesusr.com/ugd/54b9a1_00fa7fc7b0c64a58ac1f191d3d96d4f1.pdf?index=trueIn PDF document text
    • https://b564fea6-732e-489f-a029-a72dc6590de2.filesusr.com/ugd/6a4619_52769e1cefd44227af682d27d100cdee.pdf?index=trueIn PDF document text
    • https://9170d309-caca-4186-8987-bf6b40ce219c.filesusr.com/ugd/baef12_696714b07b5444b6b773b94dcc7cf17f.pdf?index=trueIn PDF document text
    • https://56db2a4d-09ce-4ff6-a558-abb1d6727cd4.filesusr.com/ugd/003b86_1bdc2fd1332742c6b617c600e43bc069.pdf?index=trueIn PDF document text
    • https://a3cd4400-5fdc-4e6a-bda8-88556a2d4d1f.filesusr.com/ugd/2f7489_1e52296c6c5343e1804dff49feaf0b53.pdf?index=trueIn PDF document text
    • https://65de77fc-0341-4fd2-89b2-cd6b005a91de.filesusr.com/ugd/cf79db_4b51b529027643cd96598e779a07fdf4.pdf?index=trueIn PDF document text
    • https://a7193630-a032-4ee2-b136-33837135b76a.filesusr.com/ugd/fac845_4dae9a200b2144568666d280b76b9488.pdf?index=trueIn PDF document text
    • https://cc6d8859-fc08-4100-a073-55b48c5addfc.filesusr.com/ugd/238140_4e3540e9f56c440eaccbcac0b64fa13d.pdf?index=trueIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013c23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C23 5220 bytes
SHA-256: c1111741aef183d23a6771edcfa4d9e2d98d186ad744ee144411148afea397cc
font_01_sfnt_off00014df5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14DF5 10580 bytes
SHA-256: cd1df760e852437e2c7caa8d39be0364a8f87e8ed96ab628f2803f92a84b50e3