Malicious PDF — malware analysis report

Static analysis result for SHA-256 1585219d9db163b3…

MALICIOUS

PDF

83.1 KB Created: 2021-04-01 08:27:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 47e18561fc688b4b91267c691831ebed SHA-1: 7436ec29b379f028709530617e41e171d1038a76 SHA-256: 1585219d9db163b3e535f30a4015f952b1ca7ebd168bd2d800a1e16690fd7752
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, identified as a 'PDF_SEO_LINK_FARM'. The primary URL, 'https://druttle.ru/wix?keyword=suffix+ly+worksheet+year+2', suggests a keyword-stuffing or link-farming operation. While no scripts were explicitly extracted, the ML classifier strongly indicates maliciousness, and the structure points towards SEO abuse or a content distribution network for potentially harmful links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 4

  • 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.
  • 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://druttle.ru/wix?keyword=suffix+ly+worksheet+year+2
    • https://cdn-cms.f-static.net/uploads/4402724/normal_601b9a5e72269.pdf
    • https://pujuwofox.weebly.com/uploads/1/3/4/8/134882524/xarige.pdf
    • https://vajalumodo.weebly.com/uploads/1/3/4/3/134390135/2313757.pdf
    • https://ketowijogi.weebly.com/uploads/1/3/5/9/135985413/620ecb3babb193.pdf
    • https://cdn-cms.f-static.net/uploads/4420432/normal_600ce682123b8.pdf
    • https://cdn-cms.f-static.net/uploads/4369764/normal_603153e3c7a86.pdf
    • https://cdn-cms.f-static.net/uploads/4450884/normal_6042bfaba0c02.pdf
    • https://wanibezitajijo.weebly.com/uploads/1/3/6/0/136000154/f350526349b1.pdf
    • https://gevupowola.weebly.com/uploads/1/3/1/4/131483584/a46418d6d907b4.pdf
    • https://fusazalokedukek.weebly.com/uploads/1/3/4/7/134729088/d5e52d7.pdf
    • https://cdn-cms.f-static.net/uploads/4370299/normal_6050c820cc660.pdf
    • https://mabobuloxulekev.weebly.com/uploads/1/3/4/6/134692970/marubuvelene.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://e4da1597-3bb3-488b-9226-7c2c9e06e9ce.filesusr.com/ugd/db5d73_440fbd2473854756ae2e87f53e30ea41.pdf?index=true
    • https://uploads.strikinglycdn.com/files/5c45f08d-1dc0-4c73-8e9d-7bc1c31b1f38/send_html_code_in_textarea_to_php_via_form.pdf
    • https://s3.amazonaws.com/rewepalazamiso/mutants_genetic_gladiators_breeding_guide.pdf
    • https://s3.amazonaws.com/najipavez/why_is_my_sewing_machine_making_noise.pdf
    • https://uploads.strikinglycdn.com/files/69bc461d-bcc0-466a-9b1a-9193ae9bba06/wall_street_journal_prime_interest_rate_december_31_2018.pdf
    • https://s3.amazonaws.com/ronenitevodo/how_to_appcake_without_jailbreak.pdf
    • https://s3.amazonaws.com/pusixa/movies_free_telugu_latest.pdf
    • https://77da94c0-0f0a-445b-87af-e489a0b5ef66.filesusr.com/ugd/db1da1_5e28667059914804b134444a85af58b1.pdf?index=true
    • https://uploads.strikinglycdn.com/files/6acbc9c6-2914-4137-9c69-f0416ab5ad15/68631357755.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
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f09b.bin
1615983845e306da201fe7a0621814c0277fbc2916d0f2f1f641e496c1477b2c
pdf-font-stream PDF embedded font (sfnt) at offset 0xF09B 5416 bytes
font_01_sfnt_off0001031c.bin
07310c9038e5bebbb7ce9bcaf74db782d5b0fc6d346ed63d2bf681f25973d658
pdf-font-stream PDF embedded font (sfnt) at offset 0x1031C 11016 bytes
font_02_sfnt_off0001291c.bin
31aa257675234f953cb39254c73a0c002637764ec2691c470e0912636c3685cf
pdf-font-stream PDF embedded font (sfnt) at offset 0x1291C 16204 bytes