Malicious PDF — malware analysis report

Static analysis result for SHA-256 43a7997ee57b1d5c…

MALICIOUS

PDF

78.1 KB Created: 2021-04-29 18:07:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: efaefe9fb74671c1608f1949df10bfcd SHA-1: 07c167c38f0d36a637e3f529b589efb95f1f89d7 SHA-256: 43a7997ee57b1d5c49099e3ee27fd11fc1a03612eb67d90b9e9509d518987f50
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to disposable hosting, and one suspicious URL that appears to be a redirector for a phishing or malware campaign. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan. The document body, though heavily obfuscated, suggests a lure related to educational materials.

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://zajinet.ru/strik?utm_term=glencoe%252Fmcgraw-hill+answer+key+geometry PDF link annotation
    • http://muvirire.22web.org/25750183845.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://5a1138df-423b-4a5d-a7c7-36223740754e.filesusr.com/ugd/a72fa8_1b4b233144ed4c52a0ceb183d536db55.pdf?index=trueIn PDF document text
    • https://1df32be7-5e6a-491e-80e4-5c558052ef26.filesusr.com/ugd/e02e08_d8a6827fc5094115b561fa2a6d941be9.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/b6dd9221-283f-44f5-accb-43259a83e38d/relogio_monitor_cardiaco_atrio.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d983c350-cd4e-4cda-84df-9764e577acde/kamixagegibe.pdfIn PDF document text
    • https://9907981b-0bc7-4fd3-a434-169f7cdadf42.filesusr.com/ugd/575363_99fb20c1539e4d5cb408572de735e71d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/82540e77-9b8d-4c7c-873d-1a70aa01f0cf/biofloc_fish_farming_book_bangla.pdfIn PDF document text
    • http://nivufebolira.epizy.com/mcgraw_hill_connect_spanish_1_answers.pdfIn PDF document text
    • https://006b50d4-ad2a-4261-8279-34542eb0d7b0.filesusr.com/ugd/a640e9_5221ee0f90944192994c1914ec80ac1c.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/97dedf77-5309-45ae-95c7-58c935d925ab/16102307861.pdfIn PDF document text
    • https://1a2149e7-ca7f-4e7c-a584-0e483de6f3af.filesusr.com/ugd/9219f8_d010fc53739048709ee33181f21e89ae.pdf?index=trueIn PDF document text
    • https://2a983b51-2e13-4971-8c1f-a5bca3ab4353.filesusr.com/ugd/e1a791_436d7c7dec9e41569d68dfc97b25d635.pdf?index=trueIn PDF document text
    • http://vewomani.rf.gd/jisatodovuwenatag.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b3958548-edbd-4b2d-99cb-19d18a1fe13a/cobra_microtalk_privacy_codes.pdfIn PDF document text
    • http://navibizo.rf.gd/avira_antivirus_security_2019_apk.pdfIn PDF document text
    • https://676a7a22-5bec-432e-92e0-9d4a0a27851c.filesusr.com/ugd/a1fb72_5f63f141eb4e46c2b3852170bcc854d6.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/b4aef749-2b1b-403d-8acc-33e0b95fdd4b/52538236428.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/89ea9f22-1db7-4584-a333-332f61378ff7/jotewusuvaxejifaxazi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8e6753d6-b3d4-406b-8c66-8c7d7e9df63e/99806042918.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f231.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF231 5568 bytes
SHA-256: 70d7aa03291e38fcd1cc70c812cd035d24aa65c89167cb141cd3d9e3c4347fca
font_01_sfnt_off00010521.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10521 11104 bytes
SHA-256: 17d6cf5a032c48db31611c63b942946a3f74adfd64c3c8addf9d3808f4ca418d