Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b1c3715c3e5f0c2…

MALICIOUS

PDF

72.3 KB Created: 2021-03-02 06:52:12 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 561b8a33961a28e13402b15a4207819a SHA-1: 713393e082c00f6ccf554f81d9a1a915907cc090 SHA-256: 8b1c3715c3e5f0c2bc4c7a88876a2d373e50c2ac69f3688c3d2009a8bb4ba515
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which are SEO-optimized and point to PDF files, suggesting a link farm or phishing operation. The document body, though heavily obfuscated, appears to be a lure related to transcript requests. ClamAV and ML classifiers also flagged this PDF as malicious, specifically as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://xajibur.ru/wix?keyword=washington+irving+high+school+transcript+request
    • http://wazepewazivulil.mywebcommunity.org/blank_outline_map_of_the_world_with_latitude_and_longitude.pdf
    • https://kesuvovim.weebly.com/uploads/1/3/5/3/135317554/9fd1f1.pdf
    • http://repair-telefonov.ru/11812779134gxqx8.pdf
    • https://gizetaxawu.weebly.com/uploads/1/3/1/8/131871526/7740775.pdf
    • https://zegesunipatobas.weebly.com/uploads/1/3/1/3/131379774/lolig-lujemigawim-lazipafolijiz.pdf
    • https://jupavovol.weebly.com/uploads/1/3/4/3/134314217/36e1e25b9.pdf
    • https://gikositaga.weebly.com/uploads/1/3/4/7/134773380/detukebepumexajen.pdf
    • https://bopojebokup.weebly.com/uploads/1/3/1/4/131408204/vagajafaberigu.pdf
    • https://nasoxuxelaleve.weebly.com/uploads/1/3/4/7/134744481/dojesiw-woxupuzazegelo.pdf
    • https://gavuvikiji.weebly.com/uploads/1/3/4/6/134674568/ribelot-dazixiki.pdf
    • http://javaxirivibewi.mygamesonline.org/how_to_adjust_the_belt_of_a_treadmill.pdf
    • http://afracheat8.xyz/40290586221choku.pdf
    • http://dombitarf.ru/53323537214rzi0y.pdf
    • https://dafelubuvotaxid.weebly.com/uploads/1/3/4/7/134753950/pejoxudexi.pdf
    • http://barbanapoli.moscow/canoscan_lide_220_installation_softwarebhv4s.pdf
    • http://figimumagoko.mygamesonline.org/gipukufevidudosajav.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://sonazorapabame.epizy.com/kuvovuzorafalisi.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dd55.bin
f35b9f790f51f916dfb76b9c24631c365928cc8a4a6066a1bda5691c9102b874
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD55 5396 bytes
font_01_sfnt_off0000efbd.bin
36e342cc701b55b5f4af866e5b12eb2f05a554bf07a4b44d5ffae78b9ba74467
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFBD 10520 bytes