Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b350e083ea18d10…

MALICIOUS

PDF

78.6 KB Created: 2021-04-03 00:53:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-28
MD5: 31088be3f37a1634e7853ed7ad905f75 SHA-1: 993d2a0638bbf81488d9ddc58a6465cb6b04377e SHA-256: 7b350e083ea18d1061fc73b018fc483a4897c123edc2a2bf990b31f3c3c59029
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO poisoning tactic. The primary URL, 'https://vilenefex.ru/award?keyword=cracking+the+code+interview+6th+edition+pdf+download', is presented as a search result for a technical book, likely to entice clicks. ClamAV and ML classifiers also flagged this PDF as malicious, indicating a high probability of malicious intent.

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://vilenefex.ru/award?keyword=cracking+the+code+interview+6th+edition+pdf+download PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4476001/normal_60460d863866f.pdfIn PDF document text
    • https://fewanisip.weebly.com/uploads/1/3/2/7/132712603/2190695.pdfIn PDF document text
    • https://cdn.sqhk.co/xafemepino/biihevY/lasologiwawotenipajetej.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369514/normal_60320e73ab10c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4445531/normal_601df7146719d.pdfIn PDF document text
    • https://jadufebifov.weebly.com/uploads/1/3/4/6/134627690/3396713.pdfIn PDF document text
    • https://cdn.sqhk.co/gatidixon/hfFjtji/1001_online_games_puzzle_connect.pdfIn PDF document text
    • https://cdn.sqhk.co/vizefejij/igihEjb/fashion_beauty_salon_bronx_ny.pdfIn PDF document text
    • https://cdn.sqhk.co/xewafazuk/cCJj8cd/boloke.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481270/normal_60357d6b2e2e9.pdfIn PDF document text
    • https://cdn.sqhk.co/mewowoji/cvhgfgg/super_one_more_jump_switch_review.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485711/normal_605ad236af657.pdfIn PDF document text
    • http://tuwasukam.getenjoyment.net/because_he_lives_chords.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/bededuxotulapil/what_to_wear_second_day_of_wedding.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/84fa1786-7b20-4ea8-8977-2fbba771feb2/the_boy_who_harnessed_the_wind_story_book.pdfIn PDF document text
    • http://sisufovofow.atwebpages.com/59769592700.pdfIn PDF document text
    • https://s3.amazonaws.com/nuxulikiwab/aerodynamics_2_notes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0552dbe5-0431-4baf-9976-49a127fd07a1/their_eyes_were_watching_god_chapter_11_quotes_explained.pdfIn PDF document text
    • https://s3.amazonaws.com/jutenojamega/zapibuwavamawaxasu.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e312.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE312 5420 bytes
SHA-256: 5aea7251fa66cf9fd8462766989629ffd5d3c91d628819c09aa7079669e970c0
font_01_sfnt_off0000f58a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF58A 11364 bytes
SHA-256: b3e289f10703917eaadb0fb819fd1893bc4d3893c993deeac1773d47569757b6
font_02_sfnt_off00011c42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C42 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176