Malicious PDF — malware analysis report

Static analysis result for SHA-256 13a4a38d4fe2f0ed…

MALICIOUS

PDF

77.6 KB Created: 2021-09-18 05:07:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8a949b69482582ec737b997ee39ff9fc SHA-1: 62f9e8774af605c373ab0889a661d0ce52d37614 SHA-256: 13a4a38d4fe2f0ed97031d7eeb2f8ac85a1a39e66d167838f3c693492ace8905
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many pointing to disposable hosting or compromised CMS upload directories, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the PDF structure itself is used to host and redirect to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9855

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://allytemp.ru/uplcv?utm_term=write+a+balanced+equation+for+the+combustion+of+butane PDF link annotation
    • https://5703n1n6999-6a55.com/contents/files/84733824498.pdfIn PDF document text
    • http://rubella2.integra-sh.com/userfiles/file/56834307240.pdfIn PDF document text
    • http://yummyschool.com/_UploadFile/Images/file/26622051911.pdfIn PDF document text
    • http://daisytalavera.com/userfiles/files/14040469061.pdfIn PDF document text
    • https://subded.org/userfiles/file/28577267538.pdfIn PDF document text
    • http://balogmihaly.hu/UserFiles/file/xibojeka.pdfIn PDF document text
    • http://sake-tori.com/images/library/File/kapikevi.pdfIn PDF document text
    • http://k12kos.com/ckfinder/userfiles/files/58182223824.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/d45f12e020b5390f917c873f641adea5/52471148863.pdfIn PDF document text
    • http://www.satunatc.ac.th/ckfinder/userfiles/files/sekatorafopidirag.pdfIn PDF document text
    • http://vietsonplastic.com/uploads/userfiles/file/90095551807.pdfIn PDF document text
    • http://holzbau-napetschnig.at/40442692160.pdfIn PDF document text
    • http://yoron.net/up/files/debezowotawepivele.pdfIn PDF document text
    • http://razzledazzleevents.in/userfiles/file/natutikodiwiwovadokifixam.pdfIn PDF document text
    • http://coimbrasoftware.hu/images/uploads/files/7319334124.pdfIn PDF document text
    • https://brazilairporttransfers.com/ckfinder/userfiles/files/tupal.pdfIn PDF document text
    • http://daiichilogistics.com/uploads/news_file/45111420889.pdfIn PDF document text
    • https://xn--hjrnskadeakademien-mtb.se/userfiles/file/83495812463.pdfIn PDF document text
    • http://thibidi.vinadesign.info/uploads/images/files/74956246503.pdfIn PDF document text
    • http://vxclouds.com/userfiles/file/fedokawenib.pdfIn PDF document text
    • https://dennismaloney.ca/upload/editor/file/darizoxusadesel.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/q2f2vlrp5qu534ht0rijkdov3m/51629778917.pdfIn PDF document text
    • https://intrigantka.ru/images/userfiles/file/16790798008.pdfIn PDF document text
    • https://bodegoncriollo.com/userfiles/file/64630909319.pdfIn PDF document text
    • http://jtylek.pl/Upload/file/zerugeboxa.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/161451def20aba---virenagakilivawalilibeji.pdfIn 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_off0000cea5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEA5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e6bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6BC 11120 bytes
SHA-256: 6ce0ff86695e51bda4eb4de61aeaec67936ea68eca7556708db91487308653f7
font_02_sfnt_off00010046.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10046 18052 bytes
SHA-256: e018c9f1de07e051210d545cec19b6798e6990c545ec7785bab56807c24c912d