Malicious PDF — malware analysis report

Static analysis result for SHA-256 c438a489c732c60e…

MALICIOUS

PDF

80.0 KB Created: 2021-03-15 17:15:45 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 57b721b6ed3a32b2e7ce6551eb9e53d9 SHA-1: e0b40331b6da50ed87435d35cfdb79ae72fb4833 SHA-256: c438a489c732c60eca78d3ec68f4704c762d3cd14b8b58de5408eaa90c182d72
196 Risk Score

Malware Insights

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

The PDF file contains numerous external links, characteristic of a link farm designed for SEO manipulation. One of the primary URLs, https://nipisod.ru/123?utm_term=business+mathematics+quiz+questions+and+answers+pdf, is identified as an SEO redirector. The file is flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicate a high probability of maliciousness, suggesting it's part of a phishing or malware distribution scheme.

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.
  • 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://nipisod.ru/123?utm_term=business+mathematics+quiz+questions+and+answers+pdf PDF link annotation
    • https://gafekiwukuwemul.weebly.com/uploads/1/3/4/3/134313713/5bdad86db2500.pdfIn PDF document text
    • https://nefupoxuwuridek.weebly.com/uploads/1/3/4/7/134747690/ditesij.pdfIn PDF document text
    • https://guxafosiwu.weebly.com/uploads/1/3/1/4/131453681/negomi_lomedizejujeme_xoluj.pdfIn PDF document text
    • https://dubuvolikumo.weebly.com/uploads/1/3/4/0/134012832/4022423.pdfIn PDF document text
    • https://fewebiporunivag.weebly.com/uploads/1/3/0/7/130775920/bipoxar_zemaxa_manitujokixagi_nimekiwovaw.pdfIn PDF document text
    • https://famosufed.weebly.com/uploads/1/3/4/9/134900490/lozeragozoxixapota.pdfIn PDF document text
    • http://vifaborabab.22web.org/58162325450.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/wipotegadodorek/juten.pdfIn PDF document text
    • http://wokezafuvix.epizy.com/anari_film_song_webmusic.pdfIn PDF document text
    • https://s3.amazonaws.com/vudivuzakal/audio_song_online_free.pdfIn PDF document text
    • https://s3.amazonaws.com/zoromexemuzid/crash_course_world_history_haitian_revolution_30_answers.pdfIn PDF document text
    • https://s3.amazonaws.com/dinilederu/endless_summer_book_3_notebook_answer.pdfIn PDF document text
    • https://91c7bc9f-df77-4dbd-ae51-8bcf521f3e61.filesusr.com/ugd/1df9ea_fa98f4c03d82418d88b033e435d16e56.pdf?index=trueIn PDF document text
    • http://rozizibuno.epizy.com/19125556853.pdfIn PDF document text
    • http://zijodere.rf.gd/arabic_remix_song_2017.pdfIn PDF document text
    • https://s3.amazonaws.com/folexapurilowe/crash_course_world_history_haitian_revolution_30_worksheet_answers.pdfIn PDF document text
    • https://728bf1be-24e3-4891-ba98-fedceca1a503.filesusr.com/ugd/3268c8_47060a0ed29142c1af1ccc85c31f9791.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/loneminovu/dealership_authorization_letter_format.pdfIn PDF document text
    • https://5862e4ea-63a6-4c92-af93-e06d02d1a664.filesusr.com/ugd/eaa371_a2f79aac52774fecb740513a7637a724.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/poresi/afdc_tanf_verification_form.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fa40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA40 5680 bytes
SHA-256: 9a7f36915e13575efac01c175a6129fbb970ffe36a345ef13b78e0b3d074e123
font_01_sfnt_off00010d80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D80 10968 bytes
SHA-256: 068f3fd91886b98245e33fd490feb00e7867baa9dbfa6ebb74be43920d944921