Malicious PDF — malware analysis report

Static analysis result for SHA-256 c81a350bd707b323…

MALICIOUS

PDF

41.9 KB Created: 2020-10-25 20:00:24 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 6f9fb04251b4828c64b3512fe48cfa91 SHA-1: 8c40eaeb846e7ab666aa6c9f823e87e0dedb9c84 SHA-256: c81a350bd707b323cbfc173520639a0e3d694f0e6f6adb2560c6acbecced0692
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to a redirector service designed to lure users to other content. The primary redirector URL is https://gettraff.ru/strik?keyword=a+separate+peace+chapter+summaries, which is flagged as malicious. This indicates a link farm or SEO poisoning attack designed to drive traffic to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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://gettraff.ru/strik?keyword=a+separate+peace+chapter+summaries In PDF document text
    • https://guwomenod.weebly.com/uploads/1/3/0/8/130873843/palaj_xofepevez.pdfIn PDF document text
    • https://senobatupubem.weebly.com/uploads/1/3/1/4/131437889/riwovekugijusez_nimudixe.pdfIn PDF document text
    • https://buliduxefexefux.weebly.com/uploads/1/3/1/6/131636978/585f7.pdfIn PDF document text
    • https://putigazabikikim.weebly.com/uploads/1/3/2/6/132682718/najobidewematexokob.pdfIn PDF document text
    • https://zuzagidebosoxe.weebly.com/uploads/1/3/4/3/134391670/af676de83c11.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/bitizopovopaso/bone_marrow_smear_preparation.pdfIn PDF document text
    • https://s3.amazonaws.com/zuxadol/rojovudokerepiwomelitexok.pdfIn PDF document text
    • https://s3.amazonaws.com/susopuzupure/kavajogasixeza.pdfIn PDF document text
    • https://s3.amazonaws.com/memul/pujotadepuxiwutefapan.pdfIn PDF document text
    • https://s3.amazonaws.com/henghuili-files2/purizo.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0504/7248/5063/files/tozesizedifetamajeken.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0502/1673/0799/files/automating_inequality_virginia_eubanks.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2b4a23be-09bf-4b43-9d10-6cee56feab67/68336978452.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3fd28827-22e2-49f5-9936-741f55ebc776/mavanurofigutijobevi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2d36b406-15f5-4072-9821-7351bdb7a527/58482402868.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3866d31c-4b83-43a6-988b-5700d1407174/gigigawumomutuxexojel.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0486/2705/6808/files/47322316123.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/3870/2748/files/where_is_my_android_sdk.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0500/9630/8410/files/35859766421.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0480/9526/4932/files/ace_electronic_water_timer_manual.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0487/9296/1189/files/76271446298.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_off00006781.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6781 5128 bytes
SHA-256: 79cf879a433dc6d2c7cd3f73939f50007848841fdda706ce41ff43f166d29826
font_01_sfnt_off000078c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x78C6 9876 bytes
SHA-256: 09c54ffd5e2228b814e849f1cc11177b13c74b589bb4128ef742b40092cdc9d7