Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac77fb1fb08a3044…

MALICIOUS

PDF

85.7 KB Created: 2021-03-16 09:44:28 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: f6b76352b980d51e134506ea152c9141 SHA-1: 22cfcd7805686674c6589c1fe218dcda90e5655d SHA-256: ac77fb1fb08a30444200f8d9389484725c33e44f6af33ada14388ef83d057650
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URIs, many pointing to disposable hosting or link farms, suggesting an attempt to redirect users to malicious sites. The document body, though heavily obfuscated, contains keywords related to 'Australian sign language alphabet pdf' and 'wkhtmltopdf', indicating a lure to disguise the malicious intent. No scripts were extracted, but the PDF structure and embedded URLs strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://xajibur.ru/123?utm_term=australian+sign+language+alphabet+pdf PDF link annotation
    • http://ujjjrrrrr.space/teoria_de_la_educacion_librozv7wc.pdfIn PDF document text
    • https://cdn.sqhk.co/lewoxiguj/eIjaImm/nisewakowiboduxorixupoda.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4530151/normal_5fc6c1c1268a9.pdfIn PDF document text
    • https://cdn.sqhk.co/zewumabigige/hgRLEje/13708898563.pdfIn PDF document text
    • http://vobigivu.22web.org/45895537297.pdfIn PDF document text
    • http://lazokiwumemo.mygamesonline.org/25628317986.pdfIn PDF document text
    • http://cmbmarketing.agency/eleanor_e_park_racismo3oo9v.pdfIn PDF document text
    • https://cdn.sqhk.co/pajokiman/kmiiSjd/vugebisojakox.pdfIn PDF document text
    • http://avit0.pro/pathfinder_polearm_feats3mcje.pdfIn PDF document text
    • http://tanolugulutewu.medianewsonline.com/fufajat.pdfIn PDF document text
    • http://artyom.guru/first_alert_carbon_monoxide_alarm_4_beeps_testyqu0f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380090/normal_602b85c1ec9b6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426822/normal_6013e3c633c8e.pdfIn PDF document text
    • http://ita-yog.space/dionne_clueless_costume_party_cityj6ncu.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4422638/normal_5ff0ab2fd9763.pdfIn PDF document text
    • http://zabolojisag.getenjoyment.net/star_trek_enterprise_season_3_episode_15_cast.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://vilepobafomunow.atwebpages.com/char_broil_infrared_grill_ribs_recipe.pdfIn PDF document text
    • http://nejovafejasujob.rf.gd/baal_veer_1107.pdfIn PDF document text
    • https://3176e400-c268-4dc0-8d69-08eae86937f8.filesusr.com/ugd/ea2f88_8e1cefa3ede04a73b67821d98a224ab1.pdf?index=trueIn PDF document text
    • http://pibusobi.epizy.com/vinupamek.pdfIn PDF document text
    • https://c183b790-cb34-49aa-848e-1a9f2b14dda3.filesusr.com/ugd/d8966e_fc8ae565684044ae9cb0005c1b3a509d.pdf?index=trueIn PDF document text
    • http://nununad.myartsonline.com/kitizigejubakopo.pdfIn PDF document text
    • https://7f06b679-e14d-4525-8955-d56a7cf6f710.filesusr.com/ugd/79e5df_f0571bf26ae14861942e1a8ed720fb84.pdf?index=trueIn 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010f93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F93 5432 bytes
SHA-256: 4d98396b153a6598ecef1a6b84e5377039c132dac5992791ea07afbfa450f77e
font_01_sfnt_off00012200.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12200 11596 bytes
SHA-256: efaddefdd20a4a96a0947e52b1e66f43d99e3b3514fa4c00808430ee27956543