Malicious PDF — malware analysis report

Static analysis result for SHA-256 843c839d7f55398f…

MALICIOUS

PDF

79.4 KB Created: 2021-01-31 22:49:10 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 4191b933531ead21842f484b1d53090b SHA-1: e58b67e11f80249f5ee253237635822123202b39 SHA-256: 843c839d7f55398f262547ae2d7429b7228ac30f3b6c8c25a1de01c73ec739e5
254 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, with at least one pointing to known malicious redirector infrastructure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. Although no scripts were extracted, the PDF structure and embedded links suggest an attempt to redirect users to malicious content.

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://yafferge.ru/123?utm_term=asphalt+8+mod+apk+for+android+10 In PDF document text
    • http://matroskin.space/principles_of_digital_communication_by_das_mullick_downloadnwshf.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408336/normal_5fce503a7615d.pdfIn PDF document text
    • https://wovufimi.weebly.com/uploads/1/3/5/3/135327312/4558916.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375909/normal_5fda24bc279bc.pdfIn PDF document text
    • http://itravelgr.com/fifavoxekoraxwyjs4.pdfIn PDF document text
    • http://hangookoil.ru/australia_zoo_koala_chlamydia_wardkg9ce.pdfIn PDF document text
    • http://delaem-sami.online/revututulos2acww.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4371497/normal_5fca9eec9232e.pdfIn PDF document text
    • https://dotawipe.weebly.com/uploads/1/3/5/3/135323210/kebilutuwawa.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/rujabepifar/bag_making_books.pdfIn PDF document text
    • https://s3.amazonaws.com/domegagowevag/yacht_crew_salary_guide_2017.pdfIn PDF document text
    • https://s3.amazonaws.com/devuxuzejozam/8616654420.pdfIn PDF document text
    • https://s3.amazonaws.com/xafaxotaful/free_irregular_plural_nouns_worksheet.pdfIn PDF document text
    • https://s3.amazonaws.com/juzinaramip/angry_birds_movie_2016_songs.pdfIn PDF document text
    • http://rigamijuzekup.rf.gd/febezobatibaxezo.pdfIn PDF document text
    • http://paguvano.epizy.com/9150124295.pdfIn PDF document text
    • https://s3.amazonaws.com/tojazudibumogab/universal_audio_710_twin-_finity_manual.pdfIn PDF document text
    • https://s3.amazonaws.com/nonipesikiri/popaguxukoxifezosuzawov.pdfIn PDF document text
    • http://xuboxigaxa.rf.gd/acadia_national_park_trail_map.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_off0000f837.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF837 5720 bytes
SHA-256: 73c9c3e692e6b0d5fd0a4d7b54caba4a6a524d362cc4fbee42441d566ea30205
font_01_sfnt_off00010b8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B8C 10796 bytes
SHA-256: d3ad1d5b2c16723b95bb2928ed3d8f755e589b226518598cdabd820f4d262e68