Malicious PDF — malware analysis report

Static analysis result for SHA-256 31c7c30313b0b018…

MALICIOUS

PDF

75.0 KB Created: 2021-04-27 14:44:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: b3a4a4da36564bb00b55015c636c7f5b SHA-1: b49f374ba1ddb144874c966afb0b2f0b5d289c21 SHA-256: 31c7c30313b0b0188ddf54272d41aa060f146589baf7a0db86d536e4299bc675
196 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to S3 buckets and other benign-looking PDFs, but also includes a redirector URL that is likely part of a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of embedded links suggests an attempt to direct users to malicious content, potentially for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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.
  • 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.
  • 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://gimoguvi.ru/strik?utm_term=excelsior+spanish+translation PDF link annotation
    • https://kosonijuzar.weebly.com/uploads/1/3/5/9/135974682/6998880.pdfIn PDF document text
    • http://rukolofi.22web.org/81333291081.pdfIn PDF document text
    • https://famixarusefon.weebly.com/uploads/1/3/4/3/134396739/natosaferomijaf.pdfIn PDF document text
    • https://sofotegepure.weebly.com/uploads/1/3/4/5/134522016/bekijipefifesu-nizizegopujedij-gujapiz-laseguwarumoje.pdfIn PDF document text
    • https://jijiwunidagaba.weebly.com/uploads/1/3/5/9/135964504/ea96b79ae362.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/jajoxulabojaso/kuzepumolofajoxupejata.pdfIn PDF document text
    • https://s3.amazonaws.com/xakapudakadu/walatekudejiwivok.pdfIn PDF document text
    • http://duzuxaxuba.epizy.com/how_much_does_wes_cost.pdfIn PDF document text
    • http://bavubuseji.epizy.com/genetica_medica_thompson.pdfIn PDF document text
    • https://s3.amazonaws.com/jugobimuraje/88985691.pdfIn PDF document text
    • https://s3.amazonaws.com/falevi/hachette_alter_ego_a1_livre.pdfIn PDF document text
    • https://s3.amazonaws.com/purufiz/63021573902.pdfIn PDF document text
    • https://s3.amazonaws.com/bomupi/fl_studio_12_mac_download_reddit.pdfIn PDF document text
    • https://s3.amazonaws.com/gizonukorad/tfs_2017_user_guide.pdfIn PDF document text
    • https://s3.amazonaws.com/kakekojezutok/occupational_health_and_safety_act_book.pdfIn PDF document text
    • https://s3.amazonaws.com/mejobu/orbit_irrigation_timer_controller_with_valve_review.pdfIn PDF document text
    • http://fevanazenanow.rf.gd/lajunewobojulesutikep.pdfIn PDF document text
    • http://tajisogekumobuk.epizy.com/rolawuzirigidobot.pdfIn PDF document text
    • https://s3.amazonaws.com/tasufagijaremo/gulagivapalu.pdfIn PDF document text
    • https://s3.amazonaws.com/rebesudanolo/18012215064.pdfIn PDF document text
    • http://jasebusezazov.rf.gd/do_ford_rangers_have_problems.pdfIn PDF document text
    • http://vilulew.rf.gd/mongodb_university_lab_answers.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_off0000e998.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE998 5048 bytes
SHA-256: 81b0ae6b1cf547678fb2e5e130db2eea67e04ab39c5ca0fb0fc6e4e56f16c0a8
font_01_sfnt_off0000fac2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAC2 10940 bytes
SHA-256: 458ffe878bd6a2479f56b767dbcd6d4b32f750d560c88d1e160a1e0a3a46d450