Malicious PDF — malware analysis report

Static analysis result for SHA-256 a071afb25c13b8f6…

MALICIOUS

PDF

71.0 KB Created: 2021-09-19 11:06:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4536ea6768d2735811c65c0a90288de8 SHA-1: fc54ae17eb87f5000d63787af34d4bdcee762b86 SHA-256: a071afb25c13b8f6af523bf815e459e16181e7efdbf9352ad6aaf769770d5885
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains embedded JavaScript and numerous external links, including one to an algorithmically generated URL, suggesting a phishing or malware distribution attempt. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for link farms, further supporting a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://philabc.ru/uplcv?utm_term=how+delete+duplicate+contacts+in+android PDF link annotation
    • http://sp2wronki.pl/fotki/fotki/file/61401310935.pdfIn PDF document text
    • https://samirkumarpaul.com/ckfinder/userfiles/files/pejowomuki.pdfIn PDF document text
    • https://www.mmgrowersg.com/ckfinder/userfiles/files/89404835024.pdfIn PDF document text
    • http://carbontuning.ru/file/soxulipudatotadabagoj.pdfIn PDF document text
    • http://carraracucinecomponibilitrapani.it/userfiles/files/54279474457.pdfIn PDF document text
    • https://thefencedocumentary.com/adminfiles/file/12191167596.pdfIn PDF document text
    • http://pc75.net/upfiles/file/1631368657.pdfIn PDF document text
    • http://av-jet.ru/userfiles/file/dojeloloxomapofokik.pdfIn PDF document text
    • https://98ing.com/upload/ck/files/20210916_065902.pdfIn PDF document text
    • https://ntiverification.com/userfiles/file/wunemerawiputawopev.pdfIn PDF document text
    • http://iweldbot.com/ckfinder/pho/files/96424603088.pdfIn PDF document text
    • http://mavelikaradiocese.org/rapha/ckfinder/userfiles/files/46603894392.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/lvso688q4cfcl6rnf5of5000m1/kupel.pdfIn PDF document text
    • http://biogenetec.tw/image/files/20210905_012751.pdfIn PDF document text
    • https://www.adoz.cz/ckfinder/userfiles/files/toxitanap.pdfIn PDF document text
    • https://fgcrubochi.com.ng/ckfinder/userfiles/files/68903035113.pdfIn PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130ce8b567d5---36201393753.pdfIn PDF document text
    • https://supermagnum-bg.com/userfiles/file/nopasakotulolaxixubej.pdfIn PDF document text
    • http://asbazainville.org/userfiles/file/petugezesadasajigivaz.pdfIn PDF document text
    • https://oreopay57.com/ckfinder/userfiles/files/70672605727.pdfIn PDF document text
    • http://park-seversk.ru/other/js/ckfinder/userfiles/files/3373002062.pdfIn PDF document text
    • http://bebelino.ru/userfiles/file/34422100232.pdfIn PDF document text
    • https://cmfnepal.org/userfiles/files/rilaxabajemaburasodu.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://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_off0000b684.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB684 15356 bytes
SHA-256: aae96a1b90677c90aa2efd14dc7b7304bb1058696fce1289fad798a5fd6e4a37
font_01_sfnt_off0000dd3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD3F 10684 bytes
SHA-256: 4eb6a52af3d607ab956a4a357da245d7a39f993d41ad6e418249c47b1b48ccff
font_02_sfnt_off0000f5de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1