Malicious PDF — malware analysis report

Static analysis result for SHA-256 b582133df1bca0f7…

MALICIOUS

PDF

76.0 KB Created: 2021-03-28 07:30:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 6bf3c81b5a0301a9f2b0f8547b605f40 SHA-1: 1abbe209cf712ba4a42a064cd04b785f85b52290 SHA-256: b582133df1bca0f781195cc6e5600cafb9ccc4d494594f420d2c66ce5e1798f3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is identified as malicious by ML classifiers and ClamAV, with critical heuristics indicating a PDF link farm. The document contains numerous external URIs, with one prominent example being a link to 'shapes of covalent molecules worksheet' which likely serves as a lure. The presence of a large number of external links suggests an attempt to direct users to potentially malicious or SEO-manipulated content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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/123?utm_term=shapes+of+covalent+molecules+worksheet
    • http://ributufukepun.66ghz.com/ac_joint_injury_exercises.pdf
    • http://circleshtang.xyz/sundari_kannal_oru_sethi_song_downloadigcxm.pdf
    • https://wipolupenigikof.weebly.com/uploads/1/3/2/7/132712614/a158f8dcd5646.pdf
    • http://salleapp.xyz/7576788696g2f46.pdf
    • http://bavewemelemare.iblogger.org/dukedutuzojomin.pdf
    • http://tumuduwaju.mypressonline.com/97497389768.pdf
    • http://fesotisifofil.mygamesonline.org/pdf_split_and_merge_basic_download_free.pdf
    • https://rewegabelera.weebly.com/uploads/1/3/5/3/135390500/fbff4.pdf
    • http://cherrypimp.online/how_to_install_verizon_fios_wifi_extenderm77kv.pdf
    • http://gosoxegekiri.mywebcommunity.org/the_economist_february_23rd_2020.pdf
    • http://kipokefurur.mygamesonline.org/applied_research_vs_basic_research.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • http://xenukelo.rf.gd/how_to_use_training_shock_collar.pdf
    • https://s3.amazonaws.com/falejogajir/philips_norelco_beard_trimmer_series_5000_bt5511_49_review.pdf
    • https://s3.amazonaws.com/pasawexawinogad/piano_sheet_music_leonard_cohen_hallelujah.pdf
    • http://tewenusewokux.rf.gd/algorithme_les_tableaux_cours.pdf
    • https://s3.amazonaws.com/fedufiporara/ripanawemepatogi.pdf
    • http://milatosokalazer.epizy.com/rotovizugepabidaxenose.pdf
    • https://s3.amazonaws.com/kovozenamofox/tatevujajadame.pdf
    • https://s3.amazonaws.com/dukajevo/bsc_bed_exam_form_2019_rajasthan.pdf
    • https://s3.amazonaws.com/tesotiwapax/22897860539.pdf
    • http://nukilaba.myartsonline.com/60422885979.pdf
    • https://s3.amazonaws.com/vipuxafol/dizuverokijijegabukebepex.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc93.bin
a474b5d52b0c00663055a1ca231c7bc9d653b7239e932af76447e6eeae1606e4
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC93 5408 bytes
font_01_sfnt_off0000eedf.bin
a3bb7bff19f726acacac3f4a3b94a260defc97cf058236380c0c1a062fd3e10a
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEDF 10840 bytes
font_02_sfnt_off000113f0.bin
1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361
pdf-font-stream PDF embedded font (sfnt) at offset 0x113F0 4324 bytes