Malicious PDF — malware analysis report

Static analysis result for SHA-256 1507757330bff633…

MALICIOUS

PDF

88.6 KB Created: 2021-09-16 19:04:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: be833e996c86dfdd901bf3281d43a33e SHA-1: 6bc6e7ae936718028f4146680a181fdf94c7149e SHA-256: 1507757330bff633b5b7d9b208d76553969b295d9dc1814a169bab684ab37296
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The sample was flagged by ML classifiers and ClamAV as malicious, with specific heuristics indicating it functions as a callback phishing lure. The document body is heavily obfuscated, preventing a detailed analysis of its content, but the presence of numerous URLs and the 'SE_CALLBACK_LURE' heuristic strongly suggest a social engineering attempt to trick the user into initiating contact via phone. The primary attack vector is likely spearphishing attachment, leading to user execution of a malicious link.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

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 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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 http://rutka.pl/media/upload/files/8f6ca1d733458099b173df8589252db8.pdf In PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131774cce985---64179978397.pdfIn PDF document text
    • http://ccshecea.org/upload/files/rolezuwutoxotivir.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/rubupudimi.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613506c68d4fc---raxepulobibozidavop.pdfIn PDF document text
    • https://mauspro.net/upload/files/goxumufenomogipasali.pdfIn PDF document text
    • http://vuoncotichdep.com/upload/files/66595604894.pdfIn PDF document text
    • http://saltokisport.com/uploads/files/tawilafonojapeberefe.pdfIn PDF document text
    • http://interstroy96.ru/uploads/files/16945589820.pdfIn PDF document text
    • http://stellarvvv.ru/ckfinder/userfiles/files/wixaxofumijev.pdfIn PDF document text
    • http://cnsgawefgl.netsociality.com/upload/files/72913487763.pdfIn PDF document text
    • http://kssi.ir/public/userfiles/file/23522675564.pdfIn PDF document text
    • https://www.chablis-gautherin.com/ckfinder/userfiles/files/punasixivipaso.pdfIn PDF document text
    • https://bvphcn.bdata.vn/upload/files/kumijubeda.pdfIn PDF document text
    • https://posaonakosovu.com/ckfinder/userfiles/files/39619046102.pdfIn PDF document text
    • http://kbautotech.com/board/datafiles/imagefile/85354090861.pdfIn PDF document text
    • https://himalayanwanderer.com/himalayan/userfiles/files/dawurolegupax.pdfIn PDF document text
    • http://turinhotelcompany.com/userfiles/files/zitegelogi.pdfIn PDF document text
    • http://commandhousecreations.com/uploads/files/42251738544.pdfIn PDF document text
    • http://huabulaw.com/uploadpic/2021-9/file/2021091122055273499.pdfIn PDF document text
    • https://benmoonpharma.com/userfiles/file/29763658965.pdfIn PDF document text
    • https://holcom-wd.holcom.vn/webroot/img/files/48250832213.pdfIn PDF document text
    • http://coachhouse.info/assets/file/31036216559.pdfIn PDF document text
    • https://superpart.com/files/nigovedugipazakewazakanil.pdfIn PDF document text
    • http://ylpqzl.com/ckfinder/userfiles/files/24095738840.pdfIn PDF document text
    • http://eaupureinternational.com/userfiles/file/sexodemimeziduna.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=kodi+update+2020+androidPDF link annotation
    • 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_off0000f677.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF677 18108 bytes
SHA-256: c40b98e8e51b9945c24063a70e8c0f9303bab8d71d7c6236beca4c6da83d855a
font_01_sfnt_off000124c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124C8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013cdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CDF 10504 bytes
SHA-256: e77ef5b1413b0be09475e2293706d4b7b3421b414fb2298559d50aa04f6f19bb