Malicious PDF — malware analysis report

Static analysis result for SHA-256 aca3ae3f754b5bb9…

MALICIOUS

PDF

79.8 KB Created: 2021-03-25 15:20:49 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: d25bae9b182495c53ef4105a69b7d01b SHA-1: a75d34025fe4bbe868f527657ec373b1120b7325 SHA-256: aca3ae3f754b5bb991c9619dee98bf0a6faa23a14cabb8b85f3c53c4d90bb044
196 Risk Score

Malware Insights

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

The PDF contains numerous external links, many of which point to SEO-optimized PDF hosting sites, a common tactic for distributing malicious content. One prominent URL, 'https://pelibifir.ru/strik?utm_term=volume+of+a+cuboid+is+12+cm3', is identified as a redirector, suggesting it's part of a phishing or malware distribution chain. The ClamAV detection and ML classifier further confirm its malicious nature, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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/strik?utm_term=volume+of+a+cuboid+is+12+cm3 PDF link annotation
    • https://tesujirigagorin.weebly.com/uploads/1/3/4/8/134869290/5972923.pdfIn PDF document text
    • http://idealica-italiaufficiale.site/zimuferemezokdrqkf.pdfIn PDF document text
    • https://jilarikogezinuv.weebly.com/uploads/1/3/0/9/130969280/3e3b74bb9c48ce3.pdfIn PDF document text
    • https://zefisuket.weebly.com/uploads/1/3/4/8/134868467/mewex.pdfIn PDF document text
    • https://bugomalaked.weebly.com/uploads/1/3/5/3/135324661/02050e66d68d.pdfIn PDF document text
    • https://pafajawu.weebly.com/uploads/1/3/2/6/132682051/medenobarapite-panilizesab-jeboxekizevo.pdfIn PDF document text
    • https://definifizuzum.weebly.com/uploads/1/3/4/7/134759181/6664290.pdfIn PDF document text
    • http://erogan-encolumbia.site/supubulofiwifezimudawawivfulw6.pdfIn PDF document text
    • https://wapojopaboxijok.weebly.com/uploads/1/3/4/7/134747084/2204531.pdfIn PDF document text
    • https://gerudupox.weebly.com/uploads/1/3/2/7/132712596/8982321.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/pisedij/intensive_and_reflexive_pronoun_worksheet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e8ceb43f-6e30-457d-8694-68c18798bc60/data_structures_and_algorithms_in_python_textbook.pdfIn PDF document text
    • https://s3.amazonaws.com/nojemi/what_are_the_12_spiritual_principles.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f8c4f2ea-f146-4971-92d9-6a8baf144766/67975626084.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4582552e-7a0a-48c9-8196-7b6e77832c0f/xerewivupodezezuj.pdfIn PDF document text
    • https://s3.amazonaws.com/toguvaju/pioneer_vsx_1022_arc.pdfIn PDF document text
    • https://s3.amazonaws.com/zuwosil/80303050426.pdfIn PDF document text
    • https://s3.amazonaws.com/sukobogixe/life_fitness_c3_upright_bike_reviews.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/05ee0421-171c-4b58-9806-fa5978b4d1c8/36348418634.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/683535ba-e730-4d60-90cc-441e9bb87cc2/john_deere_7000_planter_plates_for_sale.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_off0000e39b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE39B 5524 bytes
SHA-256: a726862815dfb93d218e7c050e99eadb36505f8bf348e082db822beb6c5db377
font_01_sfnt_off0000f662.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF662 11136 bytes
SHA-256: 88976586e03c42e78e92d5e9eda07674ecfd66fb07bdc7c44ea7e62c93ce0a5e
font_02_sfnt_off00011c9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C9C 16204 bytes
SHA-256: e93acd332f5893643511f4cefd38969ad5c744ad1b08842a788b6be7d277dd15